The ability to nominalise verbs (turn them into nouns) is arguably the single piece of grammar that lets us move away from simple clauses to more fluid expressions. The word こと translates as “something” in English, but this belies its importance to grammatical structures in Japanese. At the moment, for instance, we can say “I like pizza” but we can’t yet say “I like to eat pizza”. This is where こと comes to the rescue. But first let’s take a look at its most basic usage, as a noun that means a generic “thing”:
山田さんは彼女のことが好きです。
Yamada-san likes her.
彼のことを心配しています。
I’m worrying about him.
こと is used here to express some non-physical or conceptual thing, e.g. her “things” (looks, personality, etc.). We cannot, for example, say:
私は米のことが好きです。(✘)
I like the thing about rice.
This is because rice is a physical object—it doesn’t have traits like a personality, etc. In this case, we would just state it factually:
私は米が好きです。
I like rice.
Incidentally, it is not incorrect to say:
山田さんは彼女が好きです。
Yamada-san likes her.
However, using こと makes it a more endearing expression (emphasising that it’s not just her physical being!).
Grammatically, こと is essential to Japanese because by appending it to the standard form of a verb we can nominalise the verb (i.e. turn it into a noun) to create more complex structures.
食べる。
To eat [verb].
食べること。
The thing that is eating [noun].
Thus far we have only been able to say, “He likes (noun)”, and not, “He likes walking” or “She likes watching movies”. But now that we have nominalised the verb we can apply the grammar for “He likes (noun)” again!
寛子は食べることが好きです。
Hiroko likes eating.
幸子は歩くことが早いです。
Sachiko walks fast.
看護師の仕事は患者を介護することです。
The job of a nurse is to look after patients.
Literally the last example sentence would translate: “The job of a nurse is the thing that is to look after patients”.
こと also lets us “join verbs” to express sentences such as “to stop smoking”, “to wait to go”, “to decide to do”, etc.
鈴木さんは友達が来ることを待ちます。
Suzuki-san will wait for her friend to come.
Note that the が particle in the sub-clause directly connecting “friend” to the verb “to come” so it’s clear that Suzuki-san is doing the waiting.
明日の説明会に参加することを決めました。
I decided to go to tomorrow’s presentation.
お酒を飲むことをやめます。
I will give up drinking.
Very often こと will be changed to の when you are using it to nominalise a verb. This の is not being used as the possessive particle we met before, but rather a shorthand form of こと. This abbreviated form is used in both written and spoken Japanese.
鈴木さんは友達が来るのを待ちます。
Suzuki-san will wait for her friend to come.
お酒を飲むのをやめます。
I will give up drinking.
ロバートはテニスするのが上手です。
Robert is good at tennis.
私は本を読むのが好きです。
I like reading books.
Incidentally, these structures will very likely come up in the N5 JLPT.
〜のが上手 or 下手 or 好きです。
(He/she) is good at (or) not good at (or) likes 〜
The Strict Rules: こと vs. の
While you can often interchange こと and の, there are specific situations where you must use one and cannot use the other. These exceptions are critical for standardized testing and natural speech.
1. Use こと before です or だ. You cannot use の at the end of a sentence to mean “the act of.” (Using の creates the explanatory 〜のです / 〜んです grammar, which changes the meaning entirely).
私の趣味は映画を見ることです。
My hobby is watching movies.
2. Use こと before ができる (to be able to do).
娘は漢字を読むことができます。
My daughter can read kanji.
3. Use の for verbs of perception (seeing, hearing) and direct action (helping). Because these are immediate, sensory actions, the conceptual こと sounds unnatural.
彼が走っているのを見ました。
I saw him running.
Additionally, we can only use の in this way when it is modifying a verb or adjective. We cannot change…
大地は彼女のことが好きです。
Daichi likes her.
… into…
大地は彼女ののが好きです。(✘)
Finally, it’s worth comparing こと with its counterpart もの, which also translates as “something” in English, but the critical difference in Japanese is that もの is used to refer to a physical object.
財布はお金を入れるものです。
A wallet is something in which you put money.
鉛筆は書くものです。
A pencil is something with which you write.
包丁は台所で使うものです。
A kitchen knife is something you use in the kitchen.
We cannot replace もの with こと in any of the above sentences.
Expressing an Experience
The ability of こと to nominalise verbs also lets us express experiences, e.g. I have been to India. To do this we nominalise the past tense of the verb and add がある, the verb “to have” with its particle.
私は長崎に行ったことがあります。
I have been to Nagasaki.
Translated literally, the sentence would become: “The thing that is went to Nagasaki, I have”.
このレストランで食べたことがあります。
I have eaten at this restaurant.
沙織はブラッド・ピットに会ったことがありません。
Saori has never met Brad Pitt.
こと is the most general of nouns as well as the most common way of expressing an experience of something but equally we could use another noun like たいけん (personal experience) with this structure. Remember, all we’re really doing in modifying the noun!
私は長崎に行った体験があります。
I have a personal experience of going to Nagasaki.
Although it is translated as “have done”, “have been”, and so on in English, the emphasis is really on whether you have an experience of that thing, i.e. “Have you ever done…?” This is a very important distinction. For instance, in English we could have the following conversation:
Father
Have you done your homework?
Son
Yes, I’ve done it.
In Japanese, the following would not be a faithful translation.
父
宿題をしたことがあるの？
息子
うん、したことがあるよ。(✘)
The father isn’t asking the son whether he has ever done homework; he’s asking him whether he’s done his latest homework. In Japanese the dialogue would simply be:
父
宿題をしたの？
息子
うん、したよ。
Present Tense + ことがある
While attaching ことがある to a past-tense verb expresses an experience, attaching it to a present tense verb (in the dictionary or negative form) changes the meaning entirely. It means “There are times when…” or “Sometimes [action] happens.”
息子は朝ごはんを食べないことがあります。
There are times when my son does not eat breakfast.