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How to use the nominalizers の [no] and こと [koto] in Japanese?

By: Sachiko Dorsey
Updated

In Japanese, you can use の transcribed no and こと transcribed koto to turn and into . In grammar, we call words like these nominalizers. You’ll most often use them when an action is the or of a sentence, as in “Running is fun.” or “I practiced running.”

To turn a word into a noun in Japanese, you’ll add の transcribed no or こと transcribed koto to the plain form of a verb or adjective.

ねこは私が勉強するのをじゃましました。
Transcription: Neko wa watashi ga benkyōsuru no o jama shimashita.
Translation: My cat interfered with my studying.
私の仕事は本を書くことです。
Transcription: Watashi no shigoto wa hon o kaku koto desu.
Translation: My job is writing books.

But these two nominalizers aren’t completely interchangeable! When do you use の transcribed no and when do you use こと transcribed koto? When and how should you use a nominalized verb in a Japanese sentence? Those are all topics we’ll cover in this post! Read on and find out how to use these nominalizers correctly and effectively!

When to ONLY use the nominalizer の [no]?

When the nominalized action is happening at the same time as the main action in a , you must use の transcribed no. A bit abstract? Let’s look at some cases where you might need to use this nominalizer.

  • Perception

    When you see or hear something happening, it must be happening at the same time as you’re seeing it, so you’ll need to attach の transcribed no to the action you’re seeing.

    鳥が飛ぶのを見ました。
    Transcription: Tori ga tobu no o mimashita.
    Translation: I saw a bird flying.
    母が歌うのが聞こえます。
    Transcription: Haha ga utau no ga kikoemasu.
    Translation: I hear my mother singing.

    Here is a list of verbs of perception that commonly trigger this structure:

    Verbs of Perception
    JapaneseEnglish
    見る transcribed miru

    to see

    見える transcribed mieru

    to be visible

    聞く transcribed kiku

    to hear

    聞こえる transcribed kikoeru

    to be audible

    感じる transcribed kanjiru

    to feel

  • Acting on another action

    Use の transcribed no with the verbs that indicate how someone is interacts with another action.

    友達の授業が終わるのを待ちます。
    Transcription: Tomodachi no jugyō ga owaru no o machimasu.
    Translation: I wait for the end of my friend’s class.
    母がカレーを作るのを手伝います。
    Transcription: Haha ga karē o tsukuru no o tetsudaimasu.
    Translation: I help my mother with making curry.
    ねこは私が勉強するのをじゃましました。
    Transcription: Neko wa watashi ga benkyōsuru no o jama shimashita.
    Translation: My cat interfered with my studying.
    走るのを止めました。
    Transcription: Hashiru no o yamemashita.
    Translation: I stopped running.
  • Emphasis on a nominalized action

    の transcribed no is also used when the nominalized verb is emphasized.

    遊びに行くのはだめですよ!
    Transcription: Asobi ni iku no wa dame desuyo!
    Translation: You can’t go to play!
    Literally: Going to play isn’t good!

When to ONLY use the nominalizer こと [koto]?

When the action in the nominalized verb is not happening at the same time as the action in the , you’ll need to use こと transcribed koto to nominalize the verb. As we saw above, you just need to add it to the plain form of the verb (present or past).

Here are some cases when you’ll need to use こと transcribed koto as the nominalizer:

  • Thinking and speaking

    Use こと transcribed koto when actively talking or thinking about an action.

    先生に宿題を忘れたことを言いました。
    Transcription: Sensei ni shukudai o wasureta koto o iimashita.
    Translation: I told (my) teacher about (my) forgetting homework.
    留学することについて、先生と話しました。
    Transcription: Ryūgaku suru koto nitsuite sensei to hanashimashita.
    Translation: I spoke with my teacher about (my) studying abroad.
    日本に行くことを考えました。
    Transcription: Nihon ni iku koto o kangaemashita.
    Translation: I thought about going to Japan.
    友達が日本にいることを思いました。
    Transcription: Tomodachi ga nihon ni iru koto o omoimashita.
    Translation: I thought about my friend being in Japan.
  • The nominalized verb is a “state of being”

    We use こと transcribed koto when the nominalized action describes the subject’s general situation. In English, these are actions that follow the verb “to be,” but in Japanese the nominalized verb will be followed by an ending like 〜だ transcribed da or 〜です transcribed desu.

    私の仕事は本を書くことです。
    Transcription: Watashi no shigoto wa hon o kaku koto desu.
    Translation: My job is writing books.

    Check out our post on the state-of-being in Japanese to learn more about how to build “to be” sentences like this!

When are の [no] and こと [koto] interchangable?

In some situations, you can use either の transcribed no or こと transcribed koto with a verb plain form. The meaning doesn’t change much, but の transcribed no is more casual and colloquial to use, while こと transcribed koto elevates the formality ever so slightly. Let’s look at the situations where both nominalizers are possible!

  • Opinions or feelings about an action in general

    If expressing your general opinions or feelings about an action, you can use either の transcribed no or こと transcribed koto to nominalize the action.

    ビデオゲームを[するの・すること]は楽しいです!
    Transcription: Bideo gēmu o [suru no / suru koto] wa tanoshii desu!
    Translation: Playing video games is fun!
    私は歌を[歌うの・歌うこと]が楽しいです。
    Transcription: Watashi wa uta o [utau no / utau koto] ga suki desu.
    Translation: I like singing.
    好き transcribed suki is technically an adjective meaning “liked.”
    私は歌を[歌うの・歌うこと]が楽しいです。
    Transcription: Watashi wa uta o [utau no / utau koto] ga suki desu.
    Translation: I like singing.
    私は病院に[行くの・行くこと]が嫌いです。
    Transcription: Watashi wa byōin ni [utau no / suru koto] ga kirai desu.
    Translation: I hate going to the hospital.
    嫌い transcribed kirai is technically an adjective meaning “hated.”
  • Mental reactions to an action:

    Verbs expressing mental reactions to an action can be used with actions nominalized by either の transcribed no or こと transcribed koto.

    私は彼が[成功するの・成功すること]を信じる。
    Transcription: Watashi wa kare ga [seikō suru no / seikō suru koto] o shinjiru.
    Translation: I believe in his succeeding.
    私の家族は私が[勉強しすぎるの・勉強しすぎること]を心配している。
    Transcription: Watashi no kazoku wa watashi ga [benkyō shisugiru no / benkyō shisugiru koto] o shinpai shiteiru.
    Translation: My family is worried about my studying too much.
    母にプレゼントを[買うの・買うこと]を忘れました。
    Transcription: Haha ni purezento o [kau no / kau koto] o wasuremashita.
    Translation: I forgot to buy my mother a present.

    Note that these are mostly reactive or involuntary verbs of thinking, which makes them different from verbs for actively recollecting or considering an action, which always take actions nominalized by こと transcribed koto.

  • When nominalizing adjectives:

    In most cases, you can use either nominalizer when nominalizing adjectives. For example, you may want to say that you were surprised at the “expensiveness” of a car. You can say:

    車が高いのにおどろきました。
    Transcription: Kuruma ga takai no ni odoroki mashita.
    Translation: I was surprised at the expensiveness of a car.
    車が高いことにおどろきました。
    Transcription: Kuruma ga takai koto ni odoroki mashita.
    Translation: I was surprised at the expensiveness of a car.

    Just as you did with the verbs, take the plain form of an adjective and add の transcribed no or こと transcribed koto.

  • When nominalizing clauses:

    In most cases, you can use either の transcribed no or こと transcribed koto to nominalize a clause. We’ll discuss this more in the next section!

When to use こと [koto] and の [no] to mean “the fact that”?

You can also use の transcribed no, or sometimes こと transcribed koto, after a complete to create a phrase approximately meaning “the fact that” + clause. For example:

田中さんが学生であること
Transcription: Tanaka san ga gakusei dearu koto
Translation: (the fact) that Tanaka is a student
田中さんが学生なの
Transcription: Tanaka san ga gakusei na no
Translation: (the fact) that Tanaka is a student

In Japanese, you’ll most often use phrases like this as the object of a verb that takes a fact as its object, like 知る transcribed shirumeaning to know or わかる transcribed wakarumeaning to understand, or even some verbs of speech like 説明する transcribed setsume isurumeaning to explain.

彼は田中が学生であることを知っている。
Transcription: Kare wa Tanaka san ga gakusei dearu koto o shitte imasu.
Translation: He knows (the fact) that Tanaka is a student.

What makes these tricky, though, is that in order to attach の transcribed no or こと transcribed koto to a clause, you first need to turn that clause into an adjective. In other words, you can only attach の transcribed no and こと transcribed koto to a .

In this context, you can almost always use either の transcribed no or こと transcribed koto after a relative clause.

チェンさんが元気な[の・こと]はわかっています。
Transcription: Chen san ga genki na [no / koto] wa wakatte imasu.
Translation: I am aware of (the fact) that Chen is energetic.
チェンさんがおとなしい[の・こと]はわかっています。
Transcription: Chen san ga otonashii [no / koto] wa wakatte imasu.
Translation: I am aware of (the fact) that Chen is quiet.
チェンが昼食を食べた[の・こと]は知っています。
Transcription: Chen ga chūshoku o tabeta [no / koto] wa shitte imasu.
Translation: I know that Chen ate lunch.
田中さんが学生だった[の・こと]は知っています。
Transcription: Tanaka san ga gakusei datta [no / koto] wa shitte imasu.
Translation: I know that Tanaka was a student.

How to use nominalized words in a Japanese sentence?

Nominalized words must be treated as nouns in a Japanese sentence, which means that they’ll be marked by the same sorts of particles that usually mark nouns. Just add the particle after the nominalizer.

私はセロリを食べるのがきらいです。
Transcription: Watashi wa serori o taberu no ga kirai desu.
Translation: I dislike eating celery.
が transcribed ga marks subjects. This is literally: “Eating celery is distasteful to me.”
田中さんがアメリカに行ったことを知りませんでした。
Transcription: Tanaka san ga amerika ni itta koto o shirimasen deshita.
Translation: I didn’t know that Tanaka went to America.
を transcribed o marks direct objects.
電話がこわれたことに気がつきました。
Transcription: Denwa ga kowareta koto ni kigatsukimashita.
Translation: I noticed that my phone was broken.
に transcribed ni marks indirect objects (among other things), and it always marks the object that is noticed when using the expression 気がつく transcribed kigatsukumeaning to notice.

Summary

In this post, we’ve covered how to use の transcribed no and こと transcribed koto to nominalize words and phrases in Japanese, and when to use each one. Remember these points:

  • ONLY use の transcribed no for:

    • the objects of verbs of perception (e.g. seeing, hearing,...)

    • an action being affected by another action (e.g. helping, interfering, waiting,...)

    • an emphasized nominalized verb

  • ONLY use こと transcribed koto for:

    • objects of intentional thought and speech (e.g. telling, thinking,...)

    • when the nominalized verb is used as the predicate of a state-of-being sentence (e.g. is writing,..)

  • の transcribed no and こと transcribed koto can both be used for:

    • an action someone has general opinions or feelings about

    • the object of verbs for mental reactions to an action (e.g. worrying, forgetting,...)

    • nominalizing adjectives

    • nominalizing clauses (with some exceptions)

Now, are you ready to practice what you’ve learned? Check out our の transcribed no and こと transcribed koto exercises! Happy learning!

Meet the Author

Sachiko Dorsey

Sachiko Dorsey

Sachi was born and raised in Osaka, Japan. She has an M.A. in Japanese literature and has taught Japanese at colleges and universities for over 20 years.

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