は Particle

In Japanese, the wa は particle has multiple functions. Note that it's spelled as ha は, but pronounced like wa わ.

Manga: Boku no Hero Academia 僕のヒーローアカデミア (Chapter 46)

• Topic Marker
  
  • Argument Interpretation
  • Describing Things
    
    • Descriptions with Stative Verbs
    • Descriptions with Auxiliaries
    • Existence and Possession
    • Other Descriptions
  • Discourse Topic
  • Subordinate Clauses
  • Coordinating Clauses
  • Adjunct Clauses
  • Interrogative Pronouns
• Contrastive Topic
  
  • Implicatures
  • Two は, One Sentence
    
    • Switching Contrast
    • Subordinated Contrast
    • Cancellability
• Advanced Usage
  
  • Auxiliary Focus
  • Adverb Topic
    
    • Temporal Topic
  • Copula Topic-Focus
• Compounds
• Comma Usage
• Adverbial は
  
  • Pretty Good For a Girl
  • IT SHALL NOT BE
• Replaced by も
• をば
• References

Topic Marker

The wa は particle can mark the topic of a sentence in Japanese.

• neko wa doubutsu da
  猫は動物だ
  Cats are animals.
• neko wa kirei da
  猫は綺麗だ
  Cats are pretty.
• neko wa kawaii
  猫は可愛い
  Cats are cute.
• neko wa shabetta
  猫は喋った
  The cat spoke.

Above, we have sentences talking about the noun neko, describing it using a noun, or no-adjective, a na-adjective, an i-adjective, and, finally, a verb.

The wa は particle doesn't translate to the copulative verbs "is," "are" or "am" in English. Its function is purely syntactic and can't be translated to a word. Above, what translates to the copula is the predicative copula da だ and the copulative suffix -i ～い found in i-adjectives.

Nouns in Japanese have implicit definiteness and plurality, so the same word neko can be translated as "cats" when you have a kind-level predicate or as "the cat" when you have an individual-level or stage-level predicate.

Argument Interpretation

Much of the trouble understanding how wa は is used is due to interpretation: understanding what someone really means from what they literally said.

In particular, the topic is not literally the subject, the direct object, or the indirect object for the verb, which would be marked by the particles ga が, wo を, and ni に respectively, however, it can be interpreted as being any one of those arguments depending on the context.

English is a subject-prominent language. The subject of a sentence is derived syntactically, by its position, and it's then assumed to be topic.

• I ate a banana.
  • Syntax: Subject-Verb-Object.
    • I - subject.
    • Ate - verb.
    • A banana - object.
  • Here, we assume the subject is the topic.
  • "I" am the speaker, the person the listener is talking to.
  • We already know "I" exists, so it's part of the presupposition.
  • We don't know what "I" have done, so it's part of the focus.
  • The topic must be part of the presupposition.
  • So "I" is the topic, "ate a banana" is the focus.

Japanese is a topic-prominent language. The topic of a sentence is expressed syntactically, by a topic-marker, which can be assumed to also be the subject.

• watashi wa banana wo tabeta
  私はバナナを食べた
  As for me, banana ate. (literally.)
  I ate a banana. (interpretatively.)
  • "I" is not marked as subject.
  • "I" is marked as the topic.
  • But someone "ate a banana."
  • We assume the topic did it.
  • We assume the topic is the subject.

Our interpretation fill the gaps of unmarked arguments.

Above we had the direct object banana-wo already marked, but we were missing the subject, so we assumed the topic was the subject. Below, we have the opposite scenario:

• banana wa watashi ga tabeta
  バナナは私が食べた
  The banana, I ate. (literally.)
  I ate a banana. (interpretatively.)
  • watashi ga - subject.
  • ??? - object.
  • banana wa - topic.
  • We assume the topic is the missing object.

Our interpretation relies on assumptions that rely on context. Under different contexts, different assumptions are made, and the same literal phrase yields different interpretations. For example:

• The rat, the cat ate.
• The cat, the rat ate.

We can interpret the two phrases above as saying the same thing, "the cat ate the rat."

Even though syntactically they're in the same order and the words were switched around, our interpretation of the arguments doesn't switch around too.

The context here is that we know, as is common sense, that cats are bigger than rats. So we consistently assume the cat ate the rat, not vice-versa, no matter how we shuffle the words.

• John, James killed.

Above, we don't have the necessary context to interpret the phrase with certainty. John could have killed James, or vice-versa. We don't know because we know nothing about John or about James.

• gakkou wa itta
  学校は行った
  As for the school, went.

In the phrase above, we have a topic and nothing else. We'll have to guess how school relates to the verb. Which one does it mean?

• gakkou ga itta
  学校が行った
  The school went.
  • Good-bye school. Follow your dreams.
• gakkou wo itta
  学校を行った
  Went through the school.
  • The school is our means of going.
• gakkou ni itta
  学校に行った
  Went to the school.
  • The school is our goal.

Naturally, our interpretation is that the last phrase would be what it really means, based solely on our humble assumption that schools don't normally grow legs and start walking around all over the place. (and trust me, there's at least one anime in which this does happen. I've seen it.)

• watashi wa Tanaka desu
  私は田中です
  I'm Tanaka.
• watashi wa Tanaka da
  私は田中だ
  (same meaning.)
• watashi wa Tanaka
  私は田中
  (also same meaning.)
• watashi wa gakusei
  私は学生
  I'm an student.
• watashi wa shiawase
  私は幸せ
  I'm happy.

The phrases above lead us to believe we can reasonably expect watashi wa L to mean "I'm L."

However, that entirely depends on context. For example, behold the following context-less phrase:

• watashi wa neko
  私は猫
  I'm a cat.

Seems legit. Plenty of talking cats in anime, cat-girls, too. It could totally mean that.

Now, imagine the following context: a group of three friends are talking about their favorite animals. The first one says:

• ore wa inu ga suki
  俺は犬が好き
  As for me, dogs are liked.
  I like dogs.

Immediately, the second one follows:

• watashi wa neko
  私は猫
  As for me, cats [are liked].
  I [like] cats.

Unsatisfied with merely answering the question, that person looks at the last person and says:

• kimi wa?
  君は？
  As for you, [what animal do you like]?
  [What animal do] you [like]?

As you can see, pretty much the whole thing is implied from the context. Without context there's often no way to understand what a phrase is supposed to mean in Japanese mostly because of this.

On the other hand, the opposite scenario is also common:

• usagi ga suki
  ウサギが好き
  [As for me,] bunnies are liked.
  [I] like bunnies.

Here, the interpretation is the the topic is the speaker himself. After all, in the previous sentence (kimi wa), we've marked them as the topic of the discourse. So they must be talking about themselves now.

Manga: Boku no Hero Academia 僕のヒーローアカデミア (Chapter 46)

• Context: the characters are talking about their favorite heroes. Then, Mineta Minoru 峰田実 says:
• oira wa Maunto Redhi!!
  オイラはMt.レディ！！
  I'm Mt. Lady. (no.)
  As for me, Mt. Lady. (yes.)
  • oira オイラ
    I. Me. (a first-person pronoun like ore 俺.)

Describing Things

The wa は particle is often used together with the ga が particle in a single sentence to describe features of things. For example:

• erufu wa mimi ga nagai
  エルフは耳が長い
  As for elves, ears are long.
  Elves have long ears.
• kanojo wa me ga kirei
  彼女は目が綺麗
  As for her, eyes are pretty.
  She has pretty eyes.

Sometimes, descriptions of body parts can have secondary, idiomatic meanings. For example:

• kare wa atama ga ii
  彼は頭がいい
  He's smart.
  • atama ga ii 頭がいい
    Head is good.
    Smart.
  • atama ga warui 頭が悪い
    Head is bad.
    Dumb.
• kare wa kuchi ga karui
  彼は口が軽い
  As for him, the mouth is light.
  He's loose-lipped. He can't keep a secret.
  • kuchi ga katai 口が堅い
    Mouth is hard.
    Tight-lipped.
• kare wa se ga hikui
  彼は背が低い
  As for him, the back is low.
  He's short, as in, physically, in stature.
  • chibi ちび
    Shorty. Small-y.
  • se ga takai 背が高い
    Back is high.
    Tall.

Often, such descriptions can also be done using the no の particle, which creates no-adjectives, like possessives.

• erufu no mimi wa nagai
  エルフの耳は長い
  As for the elves' ears: long are.
  The elves' ears are long.

The simple difference is that now the elves aren't the topic any longer. Their ears are topic. Depending on context, that difference can be important, specially with other functions wa は and ga が can express, like contrast and focus marking

Descriptions with Stative Verbs

The wa は particle also provides a scope for stative verbs, which are verbs that work pretty much like adjectives.

Such verbs are peculiar because their transitivity differs across languages. In Japanese, they're intransitive (only have a subject), but translate to English as transitive verbs (subject and object).

For example, wakaru 分かる means something "is understood."

• watashi wa sore ga wakaru
  私はそれが分かる
  As for me, that is understood.
  I understand that.

The verb mieru 見える means something "is seen," translating to "someone can see something."

• watashi wa yuurei ga mieru
  私は幽霊が見える
  As for me, ghosts are seen.
  I can see ghosts.

Descriptions with Auxiliaries

Similarly, the wa は particle is used when you have an auxiliary adjective attached to the noun form of a verb.

For example, with the tai たい suffix:

• watashi wa manga wo yomu
  私は漫画を読む
  As for me, manga read.
  I read manga.
• watashi wa manga ga yomi-tai
  私は漫画が読みたい
  As for me, manga is want-to-read.
  I want to read manga.

The same applies to yasui やすい, nikui にくい, and so on.

• manga wa yomi-yasui
  漫画は読みやすい
  Manga is easy-to-read.
  Manga is easy for [me] to read.
• ranobe wa yomi-nikui
  ラノベは読みにくい
  Light novels are hard-to-read.
  Light novels are difficult for [me] to read.

The same thing can also happen with the potential form:

• kana wa yomeru
  かなは読める
  Kana is able-to-read.
  [I] can read kana.
• kanji wa yomenai
  漢字は読めない
  Kanji isn't able-to-read.
  [I] can't read kanji.

Existence and Possession

In Japanese, the verbs aru ある and iru いる can express something inanimate or animate exists or is in possession of someone. These verbs, too, are intransitive, and can work with scoping.

For example:

• watashi wa okane ga aru
  私はお金がある
  As for me, money exists.
  I have money.
• watashi wa kareshi ga iru
  私は彼氏がいる
  As for me, a boyfriend exists.
  I have a boyfriend.

The negative form of iru いる is inai いない. The negative form of aru ある is the adjective nai 無い.

• watashi wa okane ga nai
  私はお金がない
  As for me, money is nonexistent.
  I don't have money.
• watashi wa kareshi ga inai
  私は彼氏がいない
  As for me, a boyfriend doesn't exist.
  I don't have a boyfriend.

Other Descriptions

There's some other stuff which is regularly scoped that's worth noting.

First, the intransitive verbs like kakaru かかる, which means "something costs," is the sense the subject is spent in order to accomplish something else.

• shujutsu wa okane ga kakaru
  手術はお金がかかる
  As for the surgery, money costs.
  The surgery costs money.
  Surgeries take money.
• chiryou wa jikan ga kakaru
  治療は時間がかかる
  As for the treatment, time costs.
  The treatment costs time.
  The treatment takes time.

Second, the adjectives suki 好き, "is liked," and kirai 嫌い, "is disliked." With these, the subject is the thing liked, and the topic is to whom that's liked, in other words, who likes what.

• watashi wa neko ga suki
  私は猫が好き
  As for me, cats are liked.
  I like cats.
• watashi wa inu ga kirai
  私は犬が嫌い
  As for me, dogs are disliked.
  I dislike dogs.

Another example:

• watashi wa kumo ga kowai
  私は蜘蛛が怖い
  As for me, spiders are scary.
  I fear spiders.

Discourse Topic

The wa は particle marks the sentence topic. The topic of the given statement. However, that's not the only topic that exists in a discourse. The discourse topic also exists, and it spans across sentences.

The discourse topic is heavily implied from context. As a rule of thumb, you don't mark a sentence topic when the discourse topic is the same thing as the word you would mark.

In practice, this means there are cases you don't mark the same thing as topic because you had marked it as topic in a previous sentence, and it's implied you're still talking about the same thing.

• banana wa oishii ne
  バナナは美味しいね
  Bananas are tasty, aren't they?
• ippai kaou!
  いっぱい買おう！
  Let's buy lots of [bananas]!

In an overwhelming majority of the cases, the discourse topic is assumed to be "me." Consequently, you hardly ever need to say watashi wa, boku wa, ore wa in Japanese, unless you want to use another function of wa は, which we'll see later.

• banana ga suki
  バナナが好き
  Like bananas.
  • I do!
• sore ga wakaru
  それが分かる
  That's understood.
  • By me!

Furthermore, in questions, the topic is assumed to be "you," since you naturally don't ask yourself questions, you ask other people questions.

• banana ga suki desu ka?
  バナナが好きですか？
  Are bananas liked?
  • anata wa banana ga suki desu ka?
    あなたはバナナが好きですか？
    As for you, are bananas liked?
    Do you like bananas?

Combined, these two facts are part of the reason why you normally don't use first person and second person pronouns in Japanese.

Subordinate Clauses

As a general rule, there's only one topic per sentence in Japanese. The topic can only be part of the main clause. Other clauses, subordinates, can't have a marked topic.

Essentially, if you have a phrase with wa は, and it becomes a subordinate clause, it automatically stops having that wa は. For example:

• yuki wa shiroi
  雪は白い
  Snow is white. (a fact.)
• watashi wa {yuki ga shiroi} to omou
  私は雪が白いと思う
  I think that {snow is white}.

Above, a fact that would normally be uttered with wa は has to be uttered with ga が because it's in a subordinate clause marked by the to と particle. In English, it becomes a "that-clause."

Changing wa は to ga が in a subordinate clause doesn't carry any special nuance. It's simply what normally happens. ^{(Heycock, 1994)}

In relative clauses, the topic of the predicative version becomes the head noun of the attributive version. For example:

• kono hon wa watashi ga katta
  この本は私が買った
  As for this book, I bought.
  I bought this book.
• {watashi ga katta} kono hon
  私が買ったこの本
  This book, [which] {I bought}.

Above, watashi ga katta became a non-essential clause, introduced by the relative pronoun "which" in English.

This happened because in the head noun "this book" we can infer we're literally holding the book in our hands or pointing to it or something. The information "I bought" isn't necessary to know which book we're talking about. Compare to this:

• hon wa watashi ga katta
  本は私が買った
  The book, I bought.
• {watashi ga katta} hon
  私が買った本
  The book [that] {I bought}.

Above, the same relative clause translates to English as essential now, introduced by the relative pronoun "that," because we wouldn't be able to tell which book we're talking about without the relative clause.

In Japanese, almost all words that can be the head noun of a relative clause can also be a topic.

• watashi wa hon wo katta
  私は本を買った
  As for me, bought the book.
  I bought the book.
• {hon wo katta} watashi
  本を買った私
  Me [who] {bought the book}.
  • Although there's only one "me" in the world, phrases like this can be used when the speakers wants to add an information about themselves that will be relevant in the sentence.
  • In English, the phrase: "the poor me couldn't afford it," features the same thing.

Light nouns like toki 時, "time," you よう, "appearance," and koto こと, "(act or thing)," are often used as relative clauses but almost never used as the topic. On the other hand, they're also often used with clauses that describe events that would otherwise have wa は.

• are wa bakuhatsu shita
  あれは爆発した
  That-thing exploded.
• {are ga bakuhatsu} shita toki
  あれが爆破した時
  The time [when] {that-thing exploded}.
  When that thing exploded.
• kare wa shinda
  彼は死んだ
  He died.
• {kare ga shinda} you da
  彼が死んだようだ
  It seems [that] {he died}.
  Apparently, {he died}.
  I heard somewhere that {he died}.
• watashi wa yatta
  私はやった
  I did.
• kore wa {watashi ga yatta} koto da
  これは私がやったことだ
  This is a thing [that] {I did}.
  This is something that I've done.
  • I must make amends.
  • Don't interfere.

When the da だ predicative copula is placed inside a relative clause, it becomes the na な attributive copula.

• kanojo wa kyuuketsuki da
  彼女は吸血鬼だ
  She is a vampire.
• {kanojo ga kyuuketsuki na} wake nai!
  彼女が吸血鬼なわけない！
  The conclusion [that] {she is a vampire} doesn't exist!
  There's no way {she is a vampire}!
  • Stop saying nonsense! If anything, she's an angel!

Similarly, it becomes the ni に particle in the adverbial form, but right now I can't think of any example where that would be relevant.

The nominalizer no の is purely syntactical, thus meaningless, and can't be used as the topic even thought it can be the head noun.

This is relevant in a lot of cases, but, in particular, in the compounds node ので, "because," and noni のに, "even thought."

• {kanojo ga kyuuketsuki na} node {wakareta} hou ga ii
  彼女が吸血鬼なので別れた方がいい
  {She's a vampire}, thus the way [in which] {separated} is good.
  Because she's a vampire, it's better if [you two] broke up.
• {kanojo ga kyuuketsuki na} noni koi shite-shimatta
  彼女が吸血鬼なのに恋してしまった
  Even though [she is a vampire], ended-up falling-in-love.

A phrase like the above can have two interpretations depending on context:

1. Someone fell in love with her, even though she's a vampire.
2. She fell in love with someone, even though she's a vampire.

In cases like this, it's likely the subject of the subordinate isn't also the subject of the main clause. Because if it was the subject of the main, the sentence would be about "her." So the speaker would probably place her in the main as topic instead:

• kanojo wa {kyuuketsuki na} noni koi shite-shimatta
  彼女は吸血鬼なのに恋してしまった
  As for her, although {is a vampire}, ended-up falling-in-love.
  Even though she {is a vampire}, [she] ended up falling in love.

Coordinating Clauses

The wa は particle can be used with coordinating clauses. However, this gets a bit tricky to explain because of the difference between English and Japanese sentences.

To have a better idea, let's elaborate:

• baka da kedo ii yatsu da
  馬鹿だけどいいヤツだ
  Is an idiot, but is a good guy.
  [He] is an idiot, but [he] is a good guy.

Above, we have the conjunction kedo, which translates to "but" in English, a coordinating conjunction used to join two independent clauses in a compound sentence.

We can say that "he is an idiot" and "he is a good guy" are two complete thoughts. So they are, indeed, independent clauses.

In Japanese, however, we haven't said "he." We merely assumed "he." If we were to add a "he" in the phrase above, we would normally do it as a topic instead of subject. Observe:

• kare wa baka da kedo ii yatsu da
  彼は馬鹿だけどいいやつだ
  He's an idiot, but [he] is a good guy.

The sentence above illustrates a problem regarding the "dependency" of clauses in Japanese. Since we have two da だ copulas, we can safely say that we do have two clauses. Both of appear to depend on the topic. But there's only one topic.

So one of these two clauses must be depending on the topic that's in the other sentence somehow. How do we divide that?

• kare wa, {baka da} kedo, ii yatsu da?
  He, although {is an idiot}, good guy is?
• kare baka da kedo {ii yatsu da}?
  He is an idiot, although {is a good guy}?

Yeah, looks like we have no idea how to divide this up. Because we don't have a {subordinate} clause, we have two coordinating clauses. It's just that they aren't "independent thoughts" like in English, because Japanese can have missing verb arguments in clauses all the time.

In cases like the above, it works just like how the discourse topic works: if you already have the topic marked in sentence once, you don't need to mark it twice.

Since both clauses talk about kare, the word only needs to be marked once.

By contrast, when the clauses talk about different things, we need two different topics:

• ou wa shinda kedo sensou wa mada tsuduku
  王は死んだけど戦争はまだ続く
  The king died, but the war still continues.

Phrases like the above are said to have contrasting topics, which is the basis of the contrastive function of wa は that we'll see later.

Adjunct Clauses

The wa は particle isn't used in adjunct clauses. But what constitutes as an adjunct in Japanese is also very tricky.

Some verb conjugations can join clauses. The -te ～て form is conjunctive. The -zu ～ず form is adverbial. So, for example:

• ou ga shinde, sensou wa owatta
  王が死んで戦争は終わった
  The king died, and the war ended.

Above, we have the te-form of shinu, shinde, and its clause's subject is marked by ga instead of wa.

In English, the word "and" would be working as a coordinating conjunction, joining two complete thoughts: "the king died" and "the war ended."

The problem is, in this sentence, we're only really talking about the fact that "the war ended." The war is the topic and it having ended is our focus. That's what we want to communicate.

It doesn't matter if the king died, or if the crown prince ascended to the throne, or if they had a change of heart, or there was a revolution against the noble class, a coup, or if famine made the campaign unsustainable. The point is: the war ended.

Again, if both clauses talk about the same topic, you can just use a topic instead:

• kare wa ukatta
  彼は受かった
  He passed-an-exam.
• kare wa nyuugaku shita
  彼は入学した
  He enter-school did.
• kare wa ukatte nyuugaku shita
  彼は受かって入学した
  He, passing the exam, enrolled school.

Interrogative Pronouns

In general, the wa は particle can't mark interrogative pronouns like nani 何, "what," dare 誰, "who," itsu いつ, "when," doko どこ, "where," and other interrogative kosoado pronouns.

he reason for this is that the "topic" must be part of the presupposition, part of what's known in the discourse, and interrogatives are never part of the presupposition, they are always something you don't know yet and want to know about.

To have a better idea, observe the following sentence:

• sensei wa dare desu ka?
  先生は誰ですか？
  The teacher is who?

Above, the questioner is asking who is the teacher. If he's asking "who" is "the teacher," that means he assumes, he presupposes, that a teacher must exist somewhere in the world.

Since sensei is part of the presupposition, it can be marked as the topic: sensei wa.

By contrast:

• *dare wa sensei desu ka?
  誰は先生ですか？
  (wrong.)

This phrase doesn't make sense because the questioner can't know "who." They don't know "who," that's why they ask "who is it?"

You can't mark something you don't know about as the topic, but it can be marked as the focus with the focus-marking function of the ga が particle.

• dare ga sensei desu ka?
  誰が先生ですか？
  Who is the teacher?

Above, dare 誰 is marked as the focus of the sentence, and, consequently, everything else is the topic. That is, the questioner presupposes someone is the teacher, but they don't know who, so that information isn't part of the presupposition.

The same question is answered with:

• watashi ga sensei da
  私が先生だ
  I am the teacher.

Above, watashi is marked as the focus again. Even though the questioner knows who watashi is part of the discourse, since "I," the answerer, is literally talking to the questioner, they hadn't known sensei was watashi. So that information was new to them, and thus is the focus.

Similarly:

• neko to inu, {suki na} no wa docchi desu ka?
  猫と犬、好きなのはどっちですか？
  Cats and dogs, the one [that] {is liked} is which?
• neko to inu, docchi ga suki desu ka?
  猫と犬、どっちが好きですか？
  Cats and dogs, which is liked?
  Which one do you like? Cats or dogs?
• neko ga suki desu
  猫が好きです
  Cats are liked.
  I like cats.

Above, the presupposition is that you must like either cats or dogs. What the questioner doesn't know is which one. So that's the focus.

The presupposition isn't necessarily true. It's merely what the phrase implies that's already known. For example, although it was presupposed that you do like either cats or dogs, you could contradict that presupposition by answering:

• docchi mo kirai
  どっちも嫌い
  Both are disliked.
  [I] hate both.

The presupposition that a teacher exists can also be defeated by saying "nobody is the teacher." Of course, if you searched the whole world, you may find a teacher. But maybe the implication is "nobody in this classroom is the teacher, he is outside, or maybe we don't have a teacher."

Contrastive Topic

The wa は particle can also mark a contrastive topic. This is kind of different from its usual topic-marking function, and has is often referred to by a distinct name: the contrastive wa は.

The simplest way it can be observed is in a compound sentence with two main clauses joined by coordinating conjunction such as kedo けど, the conjunctive ga が, or even the compound particle noni のに.

• neko wa suki da kedo inu wa kirai da
  猫は好きけど犬は嫌いだ
  Cats are liked, but dogs aren't liked.
  [I] like cats, but [I] don't like dogs.
• anime wa miru ga manga wa yomanai
  アニメは見るが漫画は読まない
  Anime, [I] watch, but manga, [I] don't read.

Above, the comments of the topics before and after the conjunctions are in contrast with each other.

Implicatures

The contrastive wa は can appear practically anywhere the usual topic wa は can appear, with the unfortunate consequence it implies things out of nowhere.

For example, take the following, completely innocent phrase:

• ocha wa ii
  お茶はいい
  Tea is good.

There's literally no way to tell if we have a contrastive topic wa は or a normal topic wa は in the sentence above. And by "literally" I mean we have to interpret and assume.

Certainly, you'd normally assume it has no contrast with anything whatsoever, since you have no reason to believe so. However, imagine you offered someone tea to drink and they said:

• "Tea is good."

Which we all know is really short for:

• "Tea is good, in contrast with everything else you have to offer, which honestly sucks. I mean, tea is the least bad thing you got. It's barely passable. In fact, it's probably only marginally better than water. Not the fancy mineral stuff, the liquid from the tap."

Clearly we don't want to say that. So the only option that we have is to avoid wa は outright and use ga が instead, which has its own set of ridiculous nuances, the one relevant here being exhaustive listing.

• ocha ga ii
  お茶がいい
  TEA is good.
  • It's the best! Nothing else compares to the good-ness of a good tea.

Two は, One Sentence

One situation where implicatures always occur is when you have two wa は particles in one main clause.

That's because you can only have one topic per sentence. Therefore the second wa は can't be the normal topic, it must be a contrastive topic.

This is particularly dangerous because it can turn any compliment into a backhanded compliment.

• kanojo wa atama ga ii
  彼女は頭がいい
  She is smart.
• kanojo wa atama wa ii
  彼女は頭はいい
  She is smart, but.........
  • .........that's all she's got going for her. Because she hasn't bathed in three days, her rent is late, her personality is annoying, her opinions on diverse political issues are repugnant, and worst of all, she thinks Kado was a good anime. Smart is the only thing she's got that is good.

This can happen in virtually any situation.

• kanojo wa hatsuon ga umai
  彼女は発音が美味い
  As for her, the pronunciation is good.
  Her pronunciation is good.
• kanojo wa hatsuon wa umai
  彼女は発音は美味い
  Her pronunciation is good, [but she sucks at grammar, vocabulary, reading comprehension, etc.]

Oppositely, the opposite happens if you do the opposite. If you said something bad using wa は, it implies that's the only bad thing, and the rest is good.

• kanojo wa atama wa warui
  彼女は頭は悪い
  She is dumb, [but she doesn't think Kado is a good anime].

Switching Contrast

In a simple sentence, the contrast is always the second wa は. That means if you want to switch the topic and contrast, you need to shuffle the words around.

• kanojo wa kyou wa ringo wo tabeta
  彼女は今日は林檎を食べた
  As for her, as for today, the apple eat-did.
  She, today, ate the apple.
  • Implying other days she doesn't eat apples.
• kyou wa kare wa ringo wo tabeta
  今日は彼は林檎を食べた
  Today, he, the apple ate.
  • Implying normally he wouldn't eat but someone else would.

Subordinated Contrast

Grammatically, the topic of the sentence must be part of the main clause in Japanese. If a wa は is found in a subordinate clause, it's assumed to be a contrastive topic by default.

This can be a bit tricky. The topic and contrast are the first things of any clause. Which means a same wa は can be interpreted as being either at the start of a super-ordinate as a topic, or at the start of a sub-ordinate as a contrast.

You'll need to parse and figure out from context if the sentence makes sense or not. For example:

• neko wa {kirai na} hito
  猫は嫌いな人
  As for cats, people [as for which] {disliked are}.
  Cats are {disliked} people.
  • The word neko being topic in the main clause makes no sense.
• {neko wa kirai na} hito
  猫は嫌いな人
  People [as for which] {as for cats, are disliked}.
  People [who] {dislike cats but...}.
  • Like dogs, or something else.

Observe the only one that makes sense is when the wa は is parsed to be contrastive inside the subordinate clause. The same phrase without contrast would be:

• {neko ga kirai na} hito
  猫が嫌いな人
  People [as for which] {cats are disliked}.
  People [who] {dislike cats}.

Cancellability

The idea implied by the contrastive topic may be cancellable. That is, we are implying something unsaid is true, but we aren't explicitly saying it, so we can clear things up by saying the opposite of what was implied.

For example:

• neko wa suki da
  猫は好きだ
  I like cats, but...
  • I don't like dogs?

Above, the implicature is that we like cats, unlike dogs, which we don't like. That isn't necessarily the case. It's merely implied. We didn't really say "I don't like dogs" in the phrase above, so we can always cancel that implicature.

• kedo arerugii da kara kaenai
  けどアレルギーだから飼えない
  But because of allergy [I] can't keep [one as pet].

For example, if the phrase above was uttered right after, the assumption that the contrast was against other animals disappear, and, instead we see the idea that in the first example (liking cats) was being contrasted against the second (having allergy therefore not keeping a pet).

Alternatively, we could even say something that is completely the opposite of the implicature:

• kedo inu wa motto suki da
  けど犬はもっと好きだ
  But I like dogs more.

Advanced Usage

There's a few advanced ways the wa は particle can be used which you'll often see in Japanese. For reference.

Auxiliary Focus

The wa は particle can mark a verb in te-form as topic, turning its auxiliary in focus. For example:

• taberu
  食べる
  To eat.
• tabete
  食べて
  (te-form.)
• tabete-iru
  食べている
  To be eating.
• tabete wa iru kedo, yasete-iru
  食べてはいるけど、痩せている
  Eating, to be, but to be losing weight.

The phrase above could mean two things depending on context, depending on what someone asked.

1. You said he's too thin, but is he eating?
   Well, eating, he is, but he's losing weight nonetheless.
2. How is he losing weight so easily? Is he not eating?
   Well, eating, he is, but he's losing weight nonetheless.

The first sounds like we're worried about their health, they're too thin, the second sounds like we're surprised by them getting in form, wondering their method.

In both cases, the idea of eating is presupposed, but whether he is or is not doing the eating is unknown, thus, is (iru) or is not (inai) is the focus, while eating is the topic.

This usage of wa は can also be contrastive. For example:

• ganbaru
  頑張る
  To try hard.
  To put effort in doing something.
  To hang in there. To be persistent.
• ganbatte hoshii
  頑張ってほしい
  [I] want [you] hang in there.
• muri shinaide
  無理しないで
  "Please don't do the unreasonable."
  • Used in the sense you don't want someone to endanger themselves doing something.
• ganbatte wa hoshii kedo, muri wa shinaide
  頑張ってはほしいけど、無理はしないで
  [I] want [you] to be persistent, but please don't do the unreasonable.
  • For example, the main heroine is rooting for the main character of the boxing manga. Since she's rooting for him, she wants him to be persistent, to hang in there. But seeing how dangerous the fights are, and how he spends all day punching things to exhaustion, she becomes apprehensive that boxing will end up sending him to the hospital. So she wants him to be persistent, but she doesn't want him to endanger himself.

As always, the te-form doesn't necessarily end in te て despite the name. For some verbs, it ends in de で instead.

• shinu
  死ぬ
  To die.
• shindeiru
  死んでいる
  To be dying.
  To be dead.
• shinde wa iru ga, yuurei dewanai
  死んではいるが、幽霊ではない
  Dead, [he] is, but a being a ghost, not.
  [He's] dead, but not a ghost.
  
  • He's a zombie, or something.

Now, you may have noticed that, in the example above, dewanai ではない, "is not," is actually divided into topic and focus. There's a reason for this that I'll explain later.

Adverb Topic

The wa は particle can also be attached to adverbs instead of nouns and verbs.

• chotto matte!
  ちょっと待って！
  Wait a bit!
  • chotto, "a bit," is a adverb.
  • In the te-form at the end of sentences, verbs can be interpreted as an order.
• chotto wa matteita
  ちょっとは待っていた
  A bit, [I've] waited.

It can also be attached to the adverbial form of adjectives. For example:

• kawaii
  可愛い
  Is cute.
• kawaiku naru
  可愛くなる
  To become cute.
• kawaiku wa naru
  可愛くはなる
  Cute, [you'll] become.
  • I'm not saying you'll become gorgeous, or smart, or rich, or whatever, but cute, you'll become.

Similarly:

• kono hito wa kirei da
  この人は綺麗だ
  This person is pretty. (predicative.)
• kirei na hito
  綺麗な人
  A pretty person. (attributive.)
  A person [that] is pretty. (as relative clause.)
• kirei ni naru
  綺麗になる
  To become pretty. (adverbial.)
• kirei ni wa naru
  綺麗にはなる
  Pretty, [you'll] become.
  • Not cute, this time, though. Just pretty.

The same principle applies to nouns.

• isha da
  医者だ
  Is a doctor.
• isha ni naru
  医者になる
  To become a doctor.
• isha ni wa naru
  医者にはなる
  A doctor, [you'll] become.
  • You won't necessarily become a surgeon, but a doctor, you'll become.

The wa は particle also be combined with the de で particle, forming the compound dewa では.

• pasokon de asobu
  パソコンで遊ぶ
  To play with the computer.
• pasokon de wa asobu
  パソコンでは遊ぶ
  With the computer, to play.
  • This phrase implies that, while someone plays with the computer, they don't play with other things besides the computer.
  • An example that makes more sense would be a little more complicated:
• {pasokon de wa asobenai} geemu
  パソコンでは遊べないゲーム
  A game [that] {with a computer, [you] can't play}.
  • In other words, it's a game you can maybe play with a smart phone, or with a console, but with a computer, it's a game you can't play.

The de で particle is often used to mark where an action takes place. If you use wa は, you can say something is true in one place, in contrast with other places. For example:

• Toukyou de hataraku
  東京で働く
  To work in Tokyo.
• Toukyou de wa mezurashii
  東京では珍しい
  In Tokyo, [it] is rare.
  • Implicature: maybe it isn't rare in Kyoto, but in Tokyo, it is.

Temporal Topic

The wa は particle can be used with temporal nouns and adverbs to say that something is true at a certain time, as opposed to at other times.

• kyou wa watashi ga banana wo tabete-inai
  今日は私がバナナを食べていない
  Today, I haven't eaten a banana.
  • Implicature: other days I eat a banana, but today, particularly, I have not.

Phrases starting with kyou wa and such are common, however, if you want to avoid the contrast, you can just say it without the wa は particle. Temporal nouns like kyou act as adverbs on their own.

• kyou watashi wa banana wo tabete-inai
  今日私はバナナを食べていない
  Today I haven't eaten a banana.
  • (no contrast.)

There are cases you'll want that contrast, though. For example:

• kondo wa ranobe wo yonde-mita
  今度はラノベを読んでみた
  This time, [I] tried to read a light novel.
  • Implicature: other times I haven't even tried.
  • miru 見る
    To see. (verb.)
    To try to do. (auxiliary verb.)

Another great example:

Manga: Kaguya-sama wa Kokurasetai ~Tensai-Tachi no Ren'ai Zunousen~ かぐや様は告らせたい～天才たちの恋愛頭脳戦～ (Chapter 14)

• Context: you don't have a girlfriend, right?
• aa... sou da na
  あー･･･そうだな
  Yeah, that's right.
• tokutei no aite to souiu kankei tte nowa nai naa
  特定の相手とそういう関係ってのは無いなぁ
  There's no such relationship with a particular [person].
  [I] don't have that sort of relationship with anyone in particular.
  • aite 相手
    Someone you do something with. (in this case, have a relationship with.)
• ima wa
  今は
  [Right] now.
• (narrator:)
• "ima wa"!
  「今は」！
  "[Right] now"!
• mukashi wa ita
  mitai na
  fun'iki ga daseru ga
  昔は居たみたいな雰囲気が出せるが
  In the past there was, kind-of-feel [it] can let out, but...
  It can be felt as "in the past there was [a girlfriend]," but...
  "In the past [I] had [a girlfriend]," is how it sounds like, but...
  • ima wa 今は, "now," contrasts with mukashi wa 昔は, "in the past."
• {ima made dare to mo tsukiatta} koto ga nakutemo uso niwa naranai
  今迄　誰とも付き合った事が無くても嘘にはならない
  Even if [he has] never {dated with anyone up until now}, it doesn't become a lie.
  • In other words, by saying ima wa we get the implicature he has dated "in the past." However, this implicature is cancellable: he can say "I've never dated, even in the past," without sounding like his first statement was a lie or his second one is contradictory.
  • ~koto ga nai ～事がない
    To have never done [something].
• hijou ni benri na kotoba!
  非常に便利な言葉！
  An extraordinarily useful word!
• {wakamono kara roujin made
  sekai-juu de
  aisareteiru}
  kotoba de aru!!
  若者から老人まで世界中で愛されている言葉である！！
  It's a word [that] {is loved all around the world, from youngsters to elders}!
• tsukatteta. 使ってた。
  tsukatteru. 使ってる。
  sakki tsukatta. さっき使った。
  Had used [the word]. Is using. Used a bit ago.

Copula Topic-Focus

In Japanese, the copula dewanai ではない clearly contains a wa は in it. Although it's often a bad idea to analyze it, since we're in an article about wa は anyway, let's give it a go.

As we already know, nai ない, "nonexistent," is the negative form of aru ある, "to exist." And this applies to the copula too: de aru である is affirmative while dewa nai ではない is negative.

The word dearu である is normally contracted to just da だ, and dewanai ではない to janai じゃない. They mean the same thing, they're just more casual.

• banana dearu バナナである
  banana da バナナだ
  Is a banana.
  "It exists as a banana."
• banana dewanai バナナではない
  banana janai バナナじゃない
  Isn't a banana.
  "As a banana, it doesn't exist."
  • Implicature: it exists as something else.
  • Like it exists as a cat: it's a cat, it isn't a banana.

Anyway, since you can say dewanai ではない, it follows you should be able to say dewa aru ではある. And, indeed, you can say it. You can contrast the fact that something "is" something:

• kare wa baka de aru
  彼は馬鹿である
  "He exists as an idiot."
  He's an idiot.
• kare wa baka de wa aru ga,
  warui hito de wa nai
  彼は馬鹿ではあるが
  悪い人ではない
  "He as an idiot exists, but as a bad person is nonexistent."
  He's an idiot, but is not a bad person.

If you can put wa in dearu, it follows you should be able to remove the wa from dewanai. That is also possible. It commonly happens when you have an adjective that requires an attributive copula but in the negative. For example:

• baka da
  馬鹿だ
  Is stupid.
• {baka na} hito
  馬鹿な人
  A person [that] {is stupid}.
  A stupid person.
• {baka denai} hito
  馬鹿でない人
  A person [that] {is not stupid}.

You could use dewanai in the attributive, but it gets you the contrastive nuance:

• {baka de wa nai} hito
  馬鹿ではない人
  A person [that] {stupid, is not}.
  • Implicature: they are something else. For example, they aren't a stupid person, they are a scheming person, and merely appear to be stupid because it's convenient for them.

Since normally you don't need such nuance in the attributive, it normally isn't used.

Compounds

The wa は can get attached to all matter of other particles.

A good example is niwa には. Any time you can have a ni に you can have a niwa には.

• watashi ni dekiru koto
  私にできること
  Things [that] are possible to me.
  Things [that] I can do.
• watashi ni wa dekiru
  私にはできる
  To me, [it] is possible.
  I can do [it].
  • Implicature: other people may not be able to do it, but I'm able to.
• watashi ni wa dekinai
  私にはできない
  To me, [it] isn't possible.
  I can't do [it].
  • Implicature: what that guy just did, I can't do, because it's impossible for me, even though it's possible for him.

And I really mean any time.

• suki na-no-ni-wa riyuu ga aru
  好きなのには理由がある
  To [it] being liked, there's a reason.
  There's a reason for [me] liking [it].

There are some cases where niwa には is normally used, but ni に is not. This happens when the meaning of the sentence depends on the contrastive function, and removing it sounds weird. For example:

• watashi ni wa kankei nai
  私には関係ない
  To me, there isn't a relationship.
  [It] isn't related to me.
  [It] has nothing to do with me.
  [It] is none of my business.
  • Implicature: it's related to somebody else.
  • It is somebody else's business, but not mine.

Another particle, e へ, "toward," which is spelled like he へ but read like e え, can become e-wa へは.

• higashi e iku
  東へ行く
  To go toward the east.
• higashi e-wa ikenai
  東へは行けない
  Toward the east, [I] can't go.
  • Implicature: I can go toward the north, though. Is north okay? Or, maybe, the south? Best I can do is north-north-east. But east? Nope. Can't go toward there. There's mountains in the way. I can't walk through mountains. The collision system won't allow it.

Likewise, kara wa からは, "from," "since," made wa までは, "to," "until."

• go-juu-nin made wa taoshita
  ５０人までは倒した
  Up to 50 people, [he] defeated.
  • Implicature: he didn't defeat 51, but 50, he did.
  • Alternatively: he was supposed to defeat 50 people without putting his hands on the floor.
  • He did defeat them, but failed the other requirement.

There's also towa とは, which has diverse functions:

• kare to aonda
  彼と遊んだ
  [I] played with him.
• kare to wa asonda
  彼とは遊んだ
  With him, [I] played.
  • Implicature: but with others I didn't.
• yaru to omotta
  やると思った
  That "do," thought.
  [I] thought that "[he would] do [it]."
• yaru to wa omotta
  やるとは思った
  That [he would] "do [it]," [I] thought.
  • Implicature: I didn't think he'd succeed.
  • Alternatively: I didn't think he'd do it so soon.

There's also a function that only shows up in towa: to define terms.

• anime to wa animeeshon no ryaku desu
  アニメとはアニメーションの略です
  "Anime" is the abbreviation of animation.
  • In this case, the topic marker isn't marking a thing (anime) that's part of the discourse.
  • Instead, it's marking the literal word ("anime"), since to と is a quoting particle.
  • The "word" anime becomes part of the discourse as we say it. Since we've said the word, it's presupposed that the word itself exists and is part of a language, even if we don't know what the word is supposed to mean. So we can mark the quoted word as the topic even if we weren't talking about anime before.

Naturally, when you have a wa は after a particle, you use the ga が particle after to avoid contrast by having two wa は particle in a single main clause. For example:

• pengin ni wa eigo ga tsuujinai
  ペンギンには英語が通じない
  To penguins, English "doesn't get through."
  Penguins can't understand English.
  • Implicature: other creatures understand English.
  • tsuujiru 通じる
    To get through.
    For a language to be understood by someone.
    For a lie or trick to work on someone.

Comma Usage

In some cases, a comma is used after the wa は in text. This usually happens in two cases.

First, when the marked word is a temporal noun.

• kyou wa, tenki ga ii desu ne
  今日は、天気がいいですね
  Today, the weather is good, isn't it?

Second, when you have an adjunct clause between wa は and the rest of the matrix clause. The comma helps avoid interpreting the topic as an embedded contrastive topic.

• watashi wa, {anime ga suki na} no de, nihongo wo benkyou suru
  私は、アニメが好きなので、日本語を勉強する
  As for me, because {anime is liked}, Japanese learn-does.
  I, because [I] {like anime}, learn Japanese.
  Because [I] {like anime}, I learn Japanese.

Adverbial は

The wa は particle can also create an adverb used to express the condition in which something happens or is true.

The topic and contrastive functions of wa は are grammatically classified as kakari-joshi 係助詞, "linking particle," but this one is a fuku-joshi 副助詞, "adverbial particle." It can't be replaced by ga が in this case.

It happens when you have a verb in te-form, its clause expressing the condition, followed by the consequence, which is normally another verb. For example:

• okane ga nai
  お金がない
  "Money is nonexistent."
  There is no money.
  To not have money.
  • The te-form of nai is nakute.
• okane ga nakute wa komaru
  お金がなくては困る
  If there's no money, then [I'll] be inconvenienced.
  • [I'm] troubled by there not being money.

This resembles how the contrastive wa は is used with verbs. However, the contrastive wa は is placed between a verb and its auxiliary, while this adverbial wa is used between a verb and another verb, not with auxiliaries.

Furthermore, note that it's very similar to simply connecting verbs through the te-form.

• okane ga nakute komatteiru
  お金がなくて困っている
  Having no money [leads to] [I'm] inconvenienced.
  No money = inconvenienced.
  [I'm] troubled by having no money.

The difference is that when you connect verbs like this, you're saying that is already true. I'm already troubled because I'm already without money. It's already happening.

By contrast, when you have wa は, you're simply establishing what would happen if the condition was true. It isn't necessarily already true and already happening.

If it's true and happening, it doesn't mean "X happened so Y." It means "because X is the case, Y is also the case." In other words, we're stressing it's still possible to make Y stop being the case if we get rid of X, or, so long as X remains true, Y will also remain true.

To have a better idea, let's see another example:

• byouki da
  病気だ
  Is sick.
  [I'm] sick.
  • This word is normally used when it's something serious, as opposed to just catching a cold, or stuff like that.
  • The te-form of the da だ copula is de で. Not to be confused with the de で that is an adverbial particle, like in de aru and de asobu.
• byouki de hatarakenai
  病気で働けない
  [I'm] sick, [so] [I] can't work.
• byouki de wa hatarakenai
  病気では働けない
  (nuanced meaning.)

In the first example, we're simply stating the facts: why can't you work? Well, I can't work because I'm sick right now, I'm in a hospital bed with fever or something like that.

In the second example we're setting a condition. If you're sick, you can't work. That doesn't mean anybody is sick right now. But if they were, they wouldn't be able to work.

Or, if someone is indeed sick right now, they can't work, while they're still sick. Once they're no longer sick, "not able to work" will be no longer true, and they'll be back to work, probably.

Pretty Good For a Girl

In English, the phrase "pretty good for a girl" means that it's impressive something was done, because it was a girl doing it. Had it been a boy, it wouldn't have been as impressive.

Sexism aside, the reason this phrase is relevant to this article is because, to say something like that in Japanese, you would use the verb suru する, plus the adverbial copula ni に, forming ni suru にする, in the te-form, ni shite にして, plus the adverbial wa は, resulting in ni shite wa にしては.

• joshi ni shite wa joudeki da
  女子にしては上出来だ
  "Being a girl, it's well-done."
  Pretty good for a girl.

As for why it works like this, it basically just does.

I mean, the most you can reduce it is removing the wa. When you have ni shite, it means the same thing as da atte, which is the te-form of de aru.

• hito ni shite hito ni arazu
  人にして人にあらず
  Being a person not being a person.
  • arazu 在らず
    The zu form of aru 在る, "to exist."

Normally, you'd assume this ni shite is simply the te-form of ni suru. However, it's different from ni suru for two reasons.

First off, ni suru normally means "to make something something else."

• joshi ni suru
  女子にする
  To make [it] a girl.
  To make [someone] a girl.

It takes quite a few leaps of logic to go from "making X into Y" to just "being Y."

Second off, the ni に of ni suru にする is merely the adverbial copula. It's used when you have a noun or na-adjective, replacing the predicative or attributive copula. When you have an i-adjective, you can just turn it into its adverbial form, with -ku ～く suffix, and you don't need ni に.

• yowaku suru
  弱くする
  To make [it] weak.
  To weaken [it].

By contrast, ni shite にして is treated as a single whole particle, so you can't replace the ni に with something else. Instead, you can just mark an i-adjective with the whole thing.

• yowai ni shite wa joudeki
  弱いにしては上出来
  Being weak, well-done.
  Pretty good for [someone] [who] is weak.

IT SHALL NOT BE

Another way the adverbial wa は is used, and actually pretty much the most common way it's sued, is to say that doing something equals bad stuff.

There are essentially three ways this happens in anime:

1. banana wo tabete wa dame desu
   バナナを食べては駄目です
   Eating bananas is "not-good."
   You're not allowed to do that.
   That's not nice. That's bad.
   Good kids don't do that.
2. banana wo tabete wa ikenai
   バナナを食べてはいけない
   Eating bananas is "can't go."
   You shouldn't eat bananas.
   Something bad is gonna happen.
   Eating bananas is no go. We won't let that pass.
   It's not a choice.
   Never ever go for banana-eating. Only villains do that.
3. banana wo tabete wa naranai
   バナナを食べてはならない
   Eating bananas "will not become."
   YOU MUSTN'T EAT THE BANANAS.
   YOU ABSOLUTELY CAN NOT DO THAT.
   IT CAN'T BE. IT SHALL NOT BE.
   WE WON'T ALLOW IT TO HAPPEN.

My creative interpretations aside, the point is that the adverbial wa は is often used when telling something that doing something is disallowed or reprehensible, so what comes after wa は is a word that dispraises what comes before wa は.

One problem about it, is that such phrases are very similar to using the nominalizer no の instead.

• banana wo taberu no wa dame da
  バナナを食べるのは駄目だ
  The act [that is] "eating a banana" is no-good.
  • Eating bananas is bad!

The difference between using te wa ては and nowa のは is that with nowa のは we're saying the whole banana-eating business is bad. It's always wrong to eat bananas.

Did you know bananas contain potassium? And potassium is radioactive? Which means bananas are radioactive. So if you eat those radioactive bananas, you'll turn into—ba, ba, ba, ba, ba—Banana-man!

Meanwhile, te-wa ては, being adverbial, implies it's bad when the bananas have been eaten. If you eat those bananas, it's going to be bad. If the action is done, what comes after wa は is consequently assumed to be true.

This means you'd use no-wa to say that doing something is always bad, the act itself is bad, but te-wa to advise someone to not do something, because in doing it, you're gonna have a bad time.

The te-wa ては can be contracted to cha ちゃ, which is easily recognizable in any anime you may ever watch.

• banana wo tabecha dame!
  バナナを食べちゃ駄目！
  (same meaning.)
• banana wa tabecha ikenai!
  バナナを食べちゃいけない！
  (same meaning.)
• banana wo tabecha naranai!
  バナナを食べちゃならない！
  (same meaning.)
  • This one is less common because naranai sounds pretty absolute—IT CAN'T BE—so it tends to be used by more important characters, like kings, which speak in a clearer, more literary way, and wouldn't be using contractions such as cha.

Furthermore, you can do the same thing to the negative form of verbs so long as you conjugated the nai ない suffix to its te-form nakute なくて, forming nakutewa なくては, contracted to nakucha なくちゃ, which can be further contracted to nakya なきゃ.

Combined with ikenai 行けない you have literally "to not do = can not go," which is two no's, which means one yes. It's a double negative. If you mustn't not be something, then you must be something. That's literally how it works.

• banana wo tabenakutewa ikenai
  バナナを食べなくてはいけない
  To not eat bananas = can not go.
  You mustn't not eat bananas.
  You must eat bananas.
  • You have to. Because you mustn't not. So you must must.
• banana wo tabenakucha ikenai
  バナナを食べなくちゃいけない
  (same meaning.)
• banana wo tabenakya ikenai
  バナナを食べなきゃいけない
  (same meaning.)

Replaced by も

The wa は particle can always be replaced by the mo も particle, which is inclusive. With some very few exceptions.

The reason this happens is because the contrastive wa は, which implies "unlike others," can always be substituted by "like others," which is the function mo も has. For example:

• kyou wa banana wo tabeta
  今日はバナナを食べた
  Today, unlike other days, [I] ate a banana.
• kyou mo banana wo tabeta
  今日もバナナを食べた
  Today, like other days, [I] ate a banana.

Well, it doesn't translate exactly like that, but that's pretty much the gist of it.

• neko wa suki
  猫は好き
  Cats are liked, [unlike other animals].
• inu mo suki
  犬も好き
  Dogs, too, are liked.

The mo も particle is also adverbial, just like the adverbial wa は, and can end up after the te-form of verbs. However, the way it's used is very different. Observe:

• korosarete wa shinu
  殺されては死ぬ
  If [you] are killed, [you] die.
• korosarete mo shinanai
  殺されても死なない
  Even if [you] are killed, [you] don't die.

Also, using te-mo adverbially like this is more common than using te-wa like this.

I mean, te-wa is pretty common with certain specific verbs, like naranai, but, broadly, there are more common ways to say the same thing. For example, you could say korosareru to instead of korosarete wa.

On the other hand, there's no more common way to say te-mo. You could say korosareta toshitemo, but that's not more common, it's just longer.

So te-mo feels more versatile and more common than te-wa.

をば

The wo-ba をば particle is a compound combining the wo を particle with the wa は particle. In order to make it easier to pronounce, it underwent rendaku 連濁, which gives the suffixed morpheme a "diacritic," dakuten 濁点, so wo-wa をは became woba をば instead.

This is a historical particle that's not really in use in modern Japanese anymore, but I thought I'd add it here for completeness. It has an emphatic function. For example:

• inochi woba kaketemo, anata wo mamorimasu
  命をばかけても、あなたを守ります
  Even if it costs [my] life, [I'll] protect you.
  • Reference: 「をば」の使い方について - oshiete.goo.ne.jp, accessed 2019-06-01.

Above, my "life," the direct object that normally would be marked by wo, is emphasized by woba.

References

• Heycock, C., 1994, February. Focus projection in Japanese. In Proceedings North East Linguistic Society (Vol. 24).