こと turns a verb phrase into a noun. 読む is “read”; 読むこと is “reading” or “to read,” something you can put in front of は, が, を, or です. With it you can say 本を読むことが好きです (I like reading books) or 趣味は料理をすることです (my hobby is cooking). It is a JLPT N4 pattern, and it is the foundation for a whole family of N4 expressions: ことができる, ことがある, ことにする, ことになる.
The hard part is not forming it but knowing when Japanese wants こと and when it wants the other nominalizer, の. In some sentences either works; in others only one is correct.
こと packages an action as an idea. の packages it as something happening in front of you.
What does こと mean?
こと literally means “thing” in the abstract sense: a matter, a fact, an idea. When you put a verb phrase in front of it, the whole phrase becomes one noun that describes the action or fact.
English does the same job with “-ing” or “to”:
- 泳ぐこと — swimming / to swim
- 日本に住むこと — living in Japan
- 約束を守ること — keeping promises
- 彼が来なかったこと — the fact that he didn’t come
Once you have that noun, it behaves like any other: it can be the subject (〜ことは難しい), the object (〜ことを忘れた), or the predicate (〜ことです).
How to form こと
Put any plain form directly before こと. Tense and negation stay inside the phrase.
| Type | Example | Meaning |
|---|---|---|
| Verb (dictionary) | 書くこと | writing |
| Verb (negative) | 書かないこと | not writing |
| Verb (past) | 書いたこと | having written |
| い-adjective | 高いこと | being expensive |
| な-adjective | 静かなこと | being quiet |
| Noun | 学生であること | being a student |
Never use the polite form before こと: 読みますこと is wrong. Politeness goes at the end of the whole sentence (…ことが好きです).
Also watch the particles inside the phrase. The object keeps を: 漢字を書くこと. Only the particle after こと changes to fit the main sentence: 漢字を書くことが難しい, 漢字を書くことを練習する.
When is こと used?
Talking about hobbies and goals. 私の趣味は〜ことです and 夢は〜ことです are the textbook uses. Here こと is required; の cannot appear before です in this meaning.
Making general statements. 早く寝ることは体にいい (going to bed early is good for you), 外国語を話すことは難しい. These sentences are about actions in general, which is exactly what こと expresses.
Reporting facts. 彼が結婚したことを知らなかった (I didn’t know that he had got married). こと here means “the fact that.”
Writing rules and instructions. Notices, school rules, and exam instructions end a sentence with こと to give a command: ここでたばこを吸わないこと (No smoking here). This is written style; you will not hear it in conversation.
Building N4 set patterns. ことができる (can), ことがある (sometimes), ことにする (decide to), and ことになる (it has been decided) all start with this same こと. If you understand the nominalizer, those patterns make sense instead of being memorised strings.
こと itself is neutral in register. It feels a little more written and abstract than の, which is why speech often prefers の where both are possible.
こと example sentences
私の趣味は写真を撮ることです。
My hobby is taking photos.
毎日練習することが大切です。
Practising every day is what matters.
本を読むことが好きです。
I like reading.
一人で海外を旅行することは、思ったより簡単だった。
Travelling abroad alone was easier than I expected.
日本語で夢を見たことを友だちに話した。
I told my friend that I’d had a dream in Japanese.
山田さんが会社をやめたことを知っていますか。
Did you know that Yamada-san quit the company?
館内で写真を撮らないこと。
No photography inside the building.
Examples 1 and 7 are the two uses where こと is the only option: a noun predicate before です, and a written instruction. In example 3, 本を読むのが好きです would be just as correct, and more common in speech. Examples 5 and 6 treat a past event as a fact to be told or known.
Nuance of こと
こと treats an action as an idea, detached from any particular moment. That is why it suits hobbies, rules, abstract statements, and facts. It is less suited to something happening right in front of you.
Because of that abstraction, こと sounds slightly more formal and more written than の. Compare 泳ぐのが好き (conversational) with 泳ぐことが好き (a little more careful, the version you would write on a form). Both are correct; the difference is tone.
Noun + のこと is a different use. 先生のこと or 私のこと means “about the teacher / about me”: 田中さんのことが好き (I like Tanaka-san, as a person). This こと follows a noun with の and does not nominalise a verb.
こと vs の
Both turn a clause into a noun. The rules below decide which one you can use.
With 好き, 嫌い, 上手, 下手, 楽しい, 難しい, and 大切, both are fine, and の is more conversational. If you are unsure, use this test: could you see or hear the action happening? Then の. Is it an idea, a rule, or something you say or know? Then こと. For the の side of this pair, see のが好き.
Common mistakes with こと
Before です as a predicate, the nominaliser must be こと. 〜のです is read as the explanatory のだ, which changes the meaning.
Verbs of seeing and hearing need の, because you perceive the event directly.
The clause before こと is always plain form. Put the politeness at the end with です.
な-adjectives keep な before こと, just as they do before any noun.
Is こと on the JLPT?
Yes. Nominalising こと is core N4 grammar and appears in both grammar and reading sections, usually in contrast with の.
At N4 you should be able to:
- Attach こと to plain verbs, adjectives, and である
- Choose こと before です and の with perception verbs
- Recognise こと inside ことができる, ことがある, ことにする, and ことになる
The classic item is a blank with こと and の as two of the options: 私の夢は歌手になる（ ）です needs こと; 雨が降っている（ ）が見えます needs の. Reading passages also use こと-ended rules in notices, such as 図書館では静かにすること.
Practice questions for こと
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私の趣味は映画を見ることです。 — My hobby is watching films.
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日本語を話すことは楽しいですが、漢字を書くことは難しいです。 — Speaking Japanese is fun, but writing kanji is hard.
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今日が友だちの誕生日だったことを忘れていた。 — I forgot that today was my friend’s birthday.
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誰かがドアをたたくのが聞こえた。 — I heard someone knocking on the door. (聞こえる needs の.)
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テストの間、携帯を使わないこと。 — Do not use your phone during the test.
Learning path for こと
Related grammar to review next
- のが好き — the の nominaliser, the partner you have to choose between.
- ことができる — nominalised verb + できる, the most common こと pattern at N4.
- ことがある — こと + ある for “there are times when,” built on the same noun.
- ということ — adds という to report a fact or explain what something means.
- こと (must do) — the sentence-final instruction use from notices and rules, covered in depth at N3.
Learn こと with Hane
Hane gives you こと-or-の choices in real sentences, so you learn which verbs demand which nominaliser. Practise こと in Hane.
FAQ about こと
What does こと (koto) mean in Japanese?
こと (koto) means “verb nominalizer”. It is JLPT N4 grammar. こと literally means “thing” in the abstract sense: a matter, a fact, an idea. When you put a verb phrase in front of it, the whole phrase becomes one noun that describes the action or fact.
How do you form こと (koto)?
Put any plain form directly before こと. Tense and negation stay inside the phrase.
What is the difference between こと and の?
こと: abstract idea or fact. の: concrete, perceived event.
What is an example sentence with こと (koto)?
私の趣味は写真を撮ることです。 — My hobby is taking photos.