Subject and Object

In grammar, the subject, the direct object, and the indirect object are types of arguments a verb can have. The concept applies to both English and Japanese, but there are differences between how the two languages express and interpret verb arguments in a sentence.

Identification

Verbs are classified according to their transitivity, which is how many arguments they can have.

Intransitive.
Transitive.
Ditransitive.

An intransitive verb only takes a subject.

The cat¹ slept.

A transitive verb takes a subject and an object.

The cat¹ ate the rat².

A ditransitive verb takes a subject, a direct object, and an indirect object.

The cat¹ gave the rat² to the dog³.
The cat¹ gave the dog³ the rat².

The two phrases above mean the same thing. The direct and indirect objects didn't change just because we moved the words around.

In English, the subject always comes before the verb and the objects always come after. The pattern is called SVO, or Subject-Verb-Object.

The grammar syntax determines the roles of the words in a sentence in English. The verb "to give," for example, works this way:

Subj. gives dir.obj. to indir.obj.
Subj. gives indir.obj. dir.obj.

Simply adding or removing "to" changes the roles of the words around.

In Japanese

In Japanese, the particles ga が, wo, を, and ni に normally mark the word coming before it as subject, direct object, and indirect object respectively.

Subj.がverb.
Subj.がdir.obj.をverb.
Subj.がdir.obj.をindir.obj.にverb.

Japanese works just like English, except the words and the grammar is all different:

neko ga nemutta
猫が眠った
The cat slept.
neko ga nezumi wo tabeta
猫がネズミを食べた
The cat ate the rat.
neko ga nezumi wo inu ni yatta
猫がネズミを犬にやった
The cat gave the rat to the dog.

Order

Generally, the subject comes first and the verb comes last, so Japanese is SOV, or Subject-Object-Verb pattern.

However, Japanese doesn't have the same syntactical restrictions English has. You can shuffle the words around and they'll keep the same roles as before, so long as they're still marked by the same particles.

Dir.obj.をindir.obj.にsubj.がverb.
Indir.obj.にsubj.がdir.obj.をverb.
Dir.obj.をindir.obj.にverb, subj.が.
Subj.が.indir.obj.にverb, dir.obj.を.

Of course, since you're saying things in a non-normal order, it will sound odd, but it won't be grammatically wrong.

Other Roles

Although ni に is often the indirect object, it's not always. Technically, it marks to whom you give something, where something is, where you are going. For reference, some notes on similar particles.

The e へ particle marks toward what direction something is going.

mirai ni iku
未来に行く
To go to the future.
mirai e iku
未来へ行く
To go toward the future.

The to と particle marks "with whom" you're doing an activity, while the de で particle marks "with what," "how," "under what circumstances," "where" you're doing it.

tomodachi to asobu
友達と遊ぶ
To play together with a friend.
To play with a friend.
geemu de asobu
ゲームで遊ぶ
To play with a game.

vs. Agent and Patient

The terms agent and patient refer to who is doing the action and who is receiving it.

In active voice, subject is the agent and the object is patient. In patient voice, the subject is the patient. So the word that would be marked by wo を becomes marked by ga が.

Furthermore, the agent of the passive is marked by the ni に particle.

neko ga nezumi wo tabeta
猫がネズミを食べた
The cat ate the rat.
nezumi ga neko ni taberareta
ネズミが猫に食べられた
The rat was eaten by the cat.

Subject and object relate to the verb. Someone has to be subject argument of the verb. If the verb is active, the subject is the agent, if the verb is passive, the subject is patient.

On the other hand, the notions of agent and patient are a matter of interpretation. The idea that they act and receive the action is consistent, but how they act and receive the action depends on context.

For example, it's possible to have a phrase with both patient subject and object in Japanese.

kare ga kazoku wo koroshita
彼が家族を殺した
He killed the family.
He killed [his] family.
- He is the subject, thus agent, so he is doing the killing.
kare ga kazoku wo korosareta
彼が家族を殺される
He (patient) killed the family.
His family was killed.
- He is the subject, thus patient, so he is receiving the killing.
- But the object for the verb is still "family."
- The "family killing" thing was done to him.
- We can assume "his" family was killed, even though we do not have a particle that indicates possessiveness in the sentence.

Theta Criterion

In general, two arguments of a verb can't have the same role. Each argument must have a different role.

This means you can't have two subjects, direct objects, or indirect objects if you only have one verb.

*~~AをBをverb~~
(no.)

But what if I want to say: "I ate a banana and an apple?" Don't I have two objects, then?

No. You have one object: "a banana and an apple." It's more than one thing, more than one word, it's a noun phrase, but as far as syntax is concerned, that still only counts as one.

*watashi ga ringo wo banana wo tabeta
~~私がりんごをバナナを食べた~~
(wrong.)
watashi ga ringo to banana wo tabeta
私がりんごとバナナを食べた
I ate a banana and an apple.

Particles tend to have more than one function. Sometimes you'll find the same particle multiple times in a s sentence but each instance is doing something different. For example:

sugu ni gakkou ni iku
すぐに学校に行く
To go to the school immediately.

Above, we have two ni に particles expressing different functions. The first creates an adverb, "immediate-ly," the second marks the indirect object, "to the school."

You can only have one type of argument per verb, but if you have two verbs, you can have two of the same argument so long as each one is associated with a different verb.

In this case, you wouldn't have a simple sentence with a single clause, but a multiple clauses instead, as each clause has only one verb.

watashi ga {neko ga nezumi wo taberareta} to omotta
私が猫がネズミを食べられたと思った
I thought that {the cat ate the rat.}

Above, the main clause has the verb omotta, "thought," while the subordinate clause has the verb "ate," taberareta.

Complement

Some sentences aren't about actions but about descriptions. In such sentences, the subject is described by a subject complement, and subject and complement are linked together by a copula.

neko ga kirei desu
猫が綺麗です
The cat is pretty.
- neko - subject.
- kirei - complement.
- desu - copula.

In English, the copula is the verb "to be," "being," "is," "are," "am."

In Japanese, the polite copula is desu, the plain copula is da, the attributive copula is na, the adverbial copula is ni, the connective copula is de, the -i ～い is a copulative suffix, -ku ～く is an adverbial copula conjugation of that -i, and, normally, the plain copula is omitted.

neko ga kirei da
猫が綺麗だ
The cat is pretty.
neko ga kirei
猫が綺麗
The cat [is] pretty.
{kirei na} neko
綺麗な猫
The cat [that] {is pretty}.
Pretty cat.
neko ga {kirei ni} naru
猫が綺麗になる
The cat becomes so [that] {[it] is pretty}.
The cat becomes pretty.
neko ga kawaii
猫が可愛い
The cat is cute.
{kawaii} neko
可愛い猫
The cat [that] {is cute}.
neko ga kawaiku naru
猫が可愛くなる
The cat becomes so [that] {[it] is pretty.}
The cat becomes pretty.

vs. Topic

In English, the subject of a sentence is often the topic. The subject is determined by syntax, and the topic by interpretation, making it a subject-prominent language.

In Japanese, the topic of a sentence is normally marked syntactically, with the wa は particle, and it's then interpreted to be the subject, making it a topic-prominent language.

neko wa nezumi wo tabeta
猫はネズミを食べた
As for the cat, the rat ate. (literally.)
The cat ate the rat. (interpretatively.)

Above, the subject isn't marked explicitly with the ga が particle. Instead, it's assumed that the topic is the subject.

nazumi wa neko ga tabeta
ネズミは猫が食べた
As for the rat, the cat ate.
The cat ate the rat.

Observe above that this time the topic takes the role of the object.

The hint in the two phrases above is that there's also one direct object and then one subject in the sentence.

Since there can't be two direct objects in the first example, the topic must be either the indirect object or the subject. Likewise, in the second sentence there's already a subject, so the topic must an object of some sort.

nezumi wa tabeta
ネズミは食べた
As for the rat, ate.

Above, it's impossible to tell without further context what argument the rat fills for the verb. It could be that the rat ate the cheese. It could be that the cat ate the rat, but not the cheese. It would depend on what we were talking about so far.

An example with a indirect object topic.

neko ga gakkou ni itta
猫が学校に行った
The cat went to school.
gakkou niwa neko ga itta
学校には猫が行った
To the school, the cat went.
gakkou wa neko ga itta
学校は猫が行った
(same meaning.)

Large and Small Subjects

In Japanese, it's possible to have a sentence that has two subjects, called large subject and small subject, where the complement of the first subject is a predicative clause formed by the second object their complement.

zou ga {hana ga nagai}
象が鼻がない
{Noses are long} is true about elephants.
Elephants have long noses.

This is called a double subject construction, and its article goes in detail about the various ways it can be used.

But wait a second, didn't I say you can't have two subjects in a single sentence before? Well, yes. But this is different, because each subject has a different function.

For example, in the usage above, the large subject (zou) is the possessor and the small subject (hana) is the possession. If we inverted the order of the subjects, the sentence wouldn't make sense anymore.

hana ga zou ga nagai
鼻が象が長い
Noses have long elephants.

One caveat is the topic. As we've seen before, the topic is normally the subject, but can sometimes be the direct object or indirect object. With double-subjects, the topic can be either large subject or small subject.

zou wa hana ga nagai
象は鼻が長い
Elephants have long noses. (likely.)
It's the elephants of noses that are long. (unlikely.)
zou wa hana ga nagai
鼻は象が長い
Noses have long elephants. (unlikely.)
It's the noses of elephants that are long. (likely.)

You can use noun phrases containing to と with either large subject or small subject.

kudamono ga {{ringo to banana} ga oishii}
果物がリンゴとバナナが美味しい
{{Apples and bananas} are tasty} is true about fruits.
Among fruits, {{apples and bananas} are delicious}.
{ringo to banana} ga {iro ga chigau}
リンゴとバナナが色が違う
{The color differs} is true about {apples and bananas}.
Apples' and bananas' color differs.
The color of {apples and bananas} is different.

Transitivity Disparity

Some verbs that would be transitive in English, taking a subject and object, are intransitive in Japanese, taking only the subject, and have the topic (as the large subject) act as a scope for the statement.

For example, the verb kakaru かかる means something "costs." In English, we say the "subject costs the object," in Japanese, "as for the large subject, the small subject costs."

shujutsu wa okane ga kakaru
手術はお金がかかる
As for the surgery, money costs.
The surgery costs money.
jikan ga kakaru
時間がかかる
Time costs.
It takes time.
It will take a while.

Some verbs do not refer to an action but instead to a quality, to a state a thing finds itself in. They're stative verbs, like wakaru 分かる, "is understood," and mieru 見える, "is seen."

watashi wa sore ga wakaru
私はそれが分かる
As for me, that-thing is understood.
I understand that.
yuurei ga mieru
幽霊が見える
Ghosts are seen.
To be able to see ghosts.

Some verbs change transitivity when they're used with certain auxiliaries, like -tai ～たい.

watashi ga hon wo yomu
私が本を読む
I read books.
watashi wa hon ga yomitai
私は本が読みたい
As for me, books are want-to-read.
I want to read books.

Or in certain forms, like potential.

hon ga yomeru
本が読める
Book is able-to-read.
To be able to read letters.

Some forms change verbs from intransitive to transitive, like the causative form.

hito ga shinu
人が死ぬ
People die.
hito wo shinaseru
人を死なせる
To let people die.
To make people die.

Dative Subject

The ni に particle can mark a dative subject in double-subject constructions. Observe:

Tarou niwa imouto ga iru
太郎には妹がいる
For Tarou, a young sister exists.
Tarou has young sister.

This often happens with potential verbs.

watashi niwa sore ga dekiru
私にはそれができる
For me, that is do-able.
I can do that.
{watashi ni dekiru} koto
私にできること
Something [that] {is do-able for me}.
Something [that] {I can do}.

Genitive Subject

In relative clauses, the subject may be marked by the no の particle.

{neko ga tabeta} nezumi
猫が食べたネズミ
The rat [that] {the cat ate}.
{neko no tabeta} nezumi
猫の食べたネズミ
(same meaning.)

In general, if something can be marked as the topic in a sentence, it can be relativized, that is, it can become the noun qualified by a relative clause.

Since the topic can be the direct object, the direct object nezumi can be qualified by the relative clause.

The topic can be either large subject or small subject. That means either of them can be qualified by the relative clause, and either of them can be inside the relative clause. Since both are subjects, they can both be marked by no の.

{hana no nagai} zou
鼻の長い象
Elephants [that] {have long noses}.
- Large subject.
- zou ga {hana ga nagai}
  象が鼻が長い
  {Nose is long} is true about the elephant.
  The elephant's {nose is long}.
{watashi no suki na} hito
私の好きな人
The person [that] {I like}.
- Small subject.
- watashi ga sono hito ga suki da
  私がその人が好きだ
  {That person is liked} is true about me.
  I like that person.

Pronoun Dropping

In English, to avoid repeating words we often use pronouns, like "he" and "she."

John saw Mary.
John thought Mary was cute.
He thought she was cute.

This happens because English has rather strict syntax requirements, so we don't normally leave a hole where an argument is supposed to go.

John saw Mary.
*Thought Mary was cute.
*John thought was cute.

In Japanese, however, it's normal to omit a pronoun where the thing it refers to can be inferred from context.

kawaii!
かわいい！
Is cute!
[Something] is cute!
[She] is cute!
[He] is cute!
[It] is cute!

In English, sometimes sentences feature a dummy "it" that refers to nothing and is used just to fill the syntactic hole opened by not having an actual subject. For example:

It's cold today.
It's raining.

Japanese doesn't have the pronoun "it."

samui
寒い
[It] is cold.

But, sometimes, Japanese uses a different verb with an actual subject.

ame ga futteiru
雨が降っている
Rain is falling from the sky.
Rain is raining.
[It] is raining.
yuki ga futteiru
雪が降っている
Snow is raining.
[It] is snowing.

In Japanese, many kinds of phrases, like opinions, are assumed to be about the speaker himself, so you don't need to say "I." And questions are assumed to be about the listener, so you don't need to say "you" either.

kami wo kitta
髪を切った
Cut hair.
[As for me,] cut hair.
[I] cut [my] hair.
kami wo kita no?
髪を切ったの？
Cut hair?
[As for you,] cut hair?
Did [you] cut [your] hair?

Above, the topic of the sentence (I and you) is inferred from whether it's a question or not. As we've seen before, the topic can be further assumed to be the subject, so the subject is inferred from the context, and pronouns become unnecessary in many cases.