Sentence-Ending Particles 終助詞

In Japanese, "sentence-ending particles," or shuujoshi 終助詞, "final particles," are particles that come at the end of a phrase and express emotion, emphasis, determination, surprise, doubt, the speaker's will, calls for attention, and other ridiculously hard to explain effects.

Usage

The sentence-ending particles are a varied bunch. Each has its own function and ways it can and can't be used, even syntactically. The only thing that they have in common is that they come at the end of whatever you have to say.

One such example is the ka か particle, which expresses doubt, question.

kore desu
これです
[It] is this.
kore desu ka?
これですか？
Is [it] this?

Adding the ka か particle implies you're unsure about something. This normally ends up translating to English as subject-verb inversion ("it is" → "is it?"), because that's how we make questions in English.

However, the way sentence-ending particles work is more similar to exclamations than hard grammar syntax and meaningful words.

For example, although ka か is normally an uncertainty, that doesn't mean all questions end with ka か, that interrogation marks will be used in Japanese, or that it's always a question.

kore?
これ？
This?
kore ka
これか
This, huh?
kore ka!
これか！
[IT'S] THIS, HUH!

Over centuries, Japanese people spoke in a way, and that way included ending the phrase with ka か when they were unsure about something. So a Japanese native grows up listening to their parents ending sentences like that when expressing such emotions. They end up absorbing the usage.

So when a native uses these particles, they don't deliberately "add" these particles to the phrase. They instinctively, naturally, and automatically do it.

It's about as natural for a Japanese native to say ka か when they're unsure about something as it is for an English native to pronounce a certain word with stress to add emphasis.

Male vs. Female

This historic, cultural development of the language and its absorption by natives also made some sentence-ending particles become used more by women than by men and vice-versa.

kore da wa
これだわ！
[It] is this! (female speaker.)
kore da zo!
これだぞ！
[It] is this! (male speaker.)

More technically, the wa わ particle is understood as softening a sentence, while the zo ぞ and ze ぜ particles are understood as intensifying it. Culturally, femininity is thought to be soft, weak, masculinity crude, intense. ^{(Ochs, cited in Cook, 1987)}

So you have a feedback loop: because women use wa わ, it's feminine, it's soft, and because it's feminine, women want to use it to sound femininely. Men could use it too, and they'd sound either soft or feminine, depending on the situation. The opposite is also true: a woman could use ze ぜ to sounds cruder, masculine.

Fluency

A telling sign that you aren't as experienced with conversational Japanese as you'd want to be is being afraid of using sentence-ending particles. They're mysterious little things, yes, but they're also the key to fluency.

watashi wa nihongo ga jouzu desu yo!
私は日本語が上手ですよ！
I'm good at Japanese, you hear me?!

If you don't have sentence-ending particles in your arsenal, your choice of phrasing gets limited.

For example, if you want to say the phrase above but you're afraid of using yo よ, because you aren't used to using it, you'll be forced to drop the emphasis, or use another word instead, and it won't sound as natural as simply using the yo よ particle.

watashi wa nihongo ga jouzu desu
私は日本語が上手です
I'm good at Japanese. (I also sound like a robot speaking Japanese.)
watashi wa hontou ni nihongo ga jouzu desu
私は本当に日本語が上手です
I'm truly good at Japanese. (it's not a lie!)

Placement

Sentence-ending particles, as the name says, are literally always used at the end of sentences, but, as always, some particles have multiple functions, so some particles that are sentence-ending in one function can also be found in the middle of the sentences in a second function.

kateru ka douka wakaranai
勝てるかどうか分からない
Whether can win isn't known.
[I] don't know if [he] can win or not.

Furthermore, not all particles at the end of a sentence are classified as sentence-ending particles. A case-marking particle, for example, can end up at the end of a sentence if it's dislocated as an afterthought.

kau yo, kore wo
買うよ、これを
[I'll] buy [it], this.
- kore wo kau yo
  これを買うよ
  [I'll] buy this.
- yo よ
  A sentence-ending particle.
- wo を
  A case-marking particle: marks the object of a clause.

Sentence-ending particles can be combined with each other in some cases, and then they won't be the last thing of a sentence, they'll be just one of the multiple things at the end of the sentence.

kore ka yo?!
これかよ？！
This?! (are you kidding me?!)

Obsolescence

Like all things and words, sentence-ending particles can become obsolete, archaic, and stop being used in the modern language, despite having its place in historic texts, period pieces, and so on.

kobun 古文
Old text. (the term for something written in classical Japanese.)

A good example of this is the wo を particle. In modern Japanese, it's only a case-marking particle that marks the object, but in old Japanese it's an "interjectory particle," kantou-joshi 間投助詞, which worked like the sentence-ending ne ね particle.

tachi-tomari mite wo wataramu
立ちとまり見てを渡らむ
(translated to modern Japanese this would be...)
tachi-todomatte mite ne, watarou
立ちとどまって見てね、渡ろう。
[I] stood still, looked [at the autumn leaves], and crossed [the river].
—Poem by the poet Fujiwara no Kintō 藤原公任, born around in the year 966. Yep, that's over a thousand years ago. Old Japanese is old.
Reference: 【古文】　助詞２４　間投助詞「や・を・よ」　（９分） - youtube.com.

List

For reference, a list of sentence-ending particles.

ka か
Doubt. Question. Uncertainty.
Also used when confirming a doubt and surprised at it.
- tomato wa yasai desu ka?
  トマトは野菜ですか？
  Are tomatoes vegetables?
- omae ka!
  お前か！
  It's you! (who was behind all this after all this time?!)
na な ^{(1st function.)}
Forbids: expresses you don't want someone to do something.
- rouka wo hashiru na!
  廊下を走るな！
  Don't run through the corridor!
- sono me de ore wo miru na!
  その目で俺を見るな！
  Don't look at me with those eyes! (those eyes that look like you're looking at a pile of garbage or something.)
- jigoku e iku na
  地獄へ行くな
  Don't go to hell.
na な ^{(2nd function.)}
Orders: just like -nasai ～なさい.
- jigoku e iki na
  地獄へ行きな
  Go to hell.
- jigoku e ikinasai
  地獄え行きなさい
  (same meaning.)
na な ^{(3rd function.)}
naa なぁ
Expresses one's opinion, sentiment, guess.
Seeks confirmation, agreement about something.
- kyou wa samui na
  今日は寒いな
  Today is cold, huh.
  Today is cold, isn't it?
- mou ichido aitai na
  もう一度会いたいな
  [I] want to meet [her] one more time, don't I? (this is what someone is thinking to themselves, not saying to someone else.)
- tomato wa yasai ka na
  トマトは野菜かな
  Tomatoes are vegetables, I guess?
- tomato wa yasai ka naa?
  トマトは野菜かなぁ？
  Are tomatoes vegetables, I wonder?
- *na ka なか
  (combines with ka か as ka na かな, not na ka.)
ne ね ^{(1st function.)}
nee ねぇ
Seeks confirmation, agreement about something. (na な can be used when talking to yourself, but ne ね is only used when talking to others.)
Also the contraction of nai ない, and in this case not a sentence-ending particle.
- kirei desu ne
  綺麗ですね
  It's pretty, isn't it?
- kirei da nee
  綺麗だねぇ
  (same meaning.)
- dou suru ka ne?
  どうするかね？
  What are [we] going to do, I wonder?
- maji yabaku ne?
  マジやばくね？
  maji yabaku nai?
  マジやばくない？
  Ain't that really [something]?
  Isn't that really [something]?
- *ne ka ねか
  (combines with ka か as ka ne かね, not ne ka.)
- *na ne なね
  *ne na ねな
  (doesn't combine with na な that has similar functions.)
ne ね ^{(2nd function.)}
Asks someone to consider something.
Expresses agreement, consideration.
Used as a break, pause, breather, while telling a story.
- ganbatte kudasai ne
  頑張ってくださいね
  Please try your best, alright?
- sou ne
  そうね
  Yeah.
  Yeah, let's see... (starts talking about a topic).
  Yeah, about that...
- kyou wa ne, sensei ga ne, gakkou de ne...
  今日はね、先生がね、学校でね・・・
  Today, you see, the teacher, you see, in the school, you see...
- ano ne, jitsu wa ne...
  あのね、実はね・・・
  Erm, you see, the truth [is], you see...
no の ^{(1st function.)}
Asks a question, expresses doubt.
Grammatically, it's a nominalizer, so, unlike, other sentence-ending particles, you don't just put it at the end of the sentence: it works as a noun, and the sentence becomes a relative clause qualifying it.
In this case, the intonation is higher.
- asobu no?
  遊ぶの？
  Are [you] going to play?
- baka na no?
  馬鹿なの？
  Are [you] stupid?
  - baka da
    馬鹿だ
    Is stupid. (uses the predicative copula da だ. To qualify the nominalizer no の, it becomes the attributive copula na な in baka na no?)
- *ka no かの
  *na no なの
  *ne no ねの
  (in any case, no の comes before, not after another sentence-ending particle. Note that na no なの is valid when the na な particle is an attributive copula¹, not a sentence-ending particle², e.g. baka na¹ no na² 馬鹿なのな, "[he] is¹ stupid, isn't [he]²?")
no の ^{(2nd function.)}
Explains a situation, a decision.
In this case, the intonation is lower, and it's generally used by women.
- baka na no
  馬鹿なの
  [He] is stupid.
- watashi wa kaeru no!
  私は帰るの！
  I'm going [home]!
no の ^{(3rd function.)}
Gives an order, asserts a determination.
- benkyou suru no!
  勉強するの！
  Study!
yo よ
Urging someone about something.
Calling someone's attention about something.
Clarifying something.
Calling for someone.
- asobou yo
  遊ぼうよ
  Let's play.
- oshiete yo
  教えてよ
  Teach [me].
- sore wa nai yo
  それはないよ
  That's not [okay]. That's against the rules. That doesn't happen.
- sonna koto shinai yo
  そんなことしないよ
  [I] don't do something like that.
- muri yo!
  無理よ！
  [That's] impossible!
- muri na no yo!
  無理なのよ！
  [It] is impossible!
  - Same as muri na no da yo, or muri nanda yo.
- maji ka yo?
  マジかよ？
  For real? Are you serious?
- sou yo!
  そうよ！
  That's so! That's right!
- sou yo ne?
  そうよね？
  That's so, right?
- baka da yo na
  馬鹿だよな
  [He] is an idiot, don't you agree?
  - dayona だよな can also be used alone to say "yep," or "what you say is right."
- waga ou yo, sensou wa mada owatte wa inai
  我が王よ、戦争はまだ終わってはいない
  My king, the war still hasn't ended.
- yaru no ka, seito-kaichou yo!
  やるのか、生徒会長よ！
  [You] gonna [fight with me], student council president?!
sa さ
saa さぁ
ssa っさ
Seeks acknowledgement of something explained.
Expresses confidence about an outcome, promise.
Calls attention to one thing, used as a breather.
- ore wa yaru sa
  俺はやるさ
  I'll do it, you'll see.
- nantoka naru sa
  なんとかなるさ
  [It'll work out somehow], you'll see.
- ore wa sa, yareru to omou
  俺はさ、やれると思う
  I, you see, think [he] can do [it].
- ano sa, ore to tsuki-awanai?
  あのさ、俺と付き合わない？
  Hey, you see, won't [you] go out with me?
- ochi-komu na sa
  落ち込むなさ
  Don't feel depressed, you know?
  Don't feel depressed, alright?
  (sa さ can come after orders in this way.)
- chou mendokute saa~
  超めんどくてさぁ～
  It's a super pain in the ass, you know~
- *sa ka さか
  *ka sa かさ
  *sa no さの
  (can't combine with doubt, since it's explaining something that is wanted to be acknowledged.)
- *sa ne さね
  *sa na さな
  (generally, it's not used with ne or na either, but in some regions ssa ne っさね means the same thing as n-da-yo んだよ.)
wa わ
Conclusion, decision, opinion.
Clarification.
Generally used by women.
- watashi da wa!
  私だわ！
  It's me!
- yarimasu wa yo
  やりますわよ
  [I'll] do [it].
- kirei wa ne
  綺麗わね
  Pretty, isn't it?
- are wa hidoi wa...
  あれは酷いわ・・・
  That was horrible.
- ore mo ieru wa
  俺も言えるわ
  I can say it too.
- *wa ka わか
  *ka wa かわ
  *wa no わの
  (can't be used with questions, since wa わ implies one's own opinion.)
- *shite wa ~~してわ~~
  *shiyou wa ~~しよう~~
  *suru na wa ~~するなわ~~
  *shi na wa ~~しなさいわ~~
  (can't be used to tell someone else what to do.)
ze ぜ
Alerts someone of your own opinion, will, decision.
Includes an idea to be considered.
Generally used by men.
- yarou ze
  やろうぜ
  Let's do it.
- katte miseru ze!
  勝ってみせるぜ！
  [I'm going] to show [you] [I'll] win!
- kare wa tsuyoi ze, kateru ka?
  彼は強いぜ、勝てるか？
  He's strong, you know, can you win?
- owatta ze
  終わったぜ
  It ended.
  [I'm] finished [doing it]. [I'm] done.
- utsukushii ze
  美しいぜ
  It's beautiful.
- ore wa chigau ze
  俺は違うぜ
  I'm different. I'm not like the others.
- kimi ni horeta-n-da ze
  君に惚れたんだぜ
  [I] fell in love with you.
- *ka ze かぜ
  *ze ka ぜか
  *ze no ぜの
  (can't combine with doubt, since it's one's own opinion.)
- *ze na ぜな
  *ze ne ぜね
  (can't combine with confirmation, since it alerts a thought or fact.)
- *shite ze ~~してぜ~~
  *suru na ze ~~するなぜ~~
  *shi na ze ~~しなぜ~~
  (can't combine with orders, since it alerts a thought or fact. The volitional, like yarou ze, is exceptional because it alerts one's own will to do something, plus an invitation. By contrast, yarou yo is calling someone else's attention to doing an activity.)
zo ぞ ^{(1st function.)}
Strongly asserts something: one's opinion, will, decision.
Asserts a correction, a reminder, an argument.
Generally used by men.
- iku zo
  行くぞ
  [I'll] go.
  [Let's] go.
  - iku ze 行くぜ would merely alert the interlocutors of your own decision, "to go," "I'll go," while iku zo asserts your will, and is likely to mean "I want to go now," "we'll be going now," "let's go."
- kore da zo!
  これだぞ！
  It's this!
- kare wa maketa zo
  彼は負けたぞ
  He lost, you know.
- *ka zo かぞ
  *zo ka ぞか
  *zo no ぞの
  (can't combine with doubt, since it's an assertion.)
- *zo na ぞな
  *zo ne ぞね
  (can't combine with confirmation, since it's an assertion.)
- *shiyou zo ~~しようぞ~~
  *shite zo ~~してぞ~~
  *suru na zo ~~するなぞ~~
  *shi na zo ~~しなぞ~~
  (can't combine with commands, since it asserts a thought or fact, not an order.)
zo ぞ ^{(2nd function.)}
Emphasizes a doubt, wonders, asks how something is, can be.
Only when it comes after nouns or verbs in the volitional form (-ou), but that don't actually show volition (let's do), the ones that show consideration (is it, I wonder?).
Historic, seen in period pieces, not used in modern Japanese.
- donna hito de arou zo?
  どんな人であろうぞ？
  [They] are what kind of person?
  - de arou であろう, from de aru である, "to be."