こと (Koto) - Japanese Focus

The word こと (koto) is a versatile noun in Japanese that is often used to refer to abstract concepts, actions, or experiences. It can be translated as “thing,” “matter,” “event,” or “fact,” depending on the context.

In Japanese grammar, こと is frequently used to nominalize verbs, turning an action into a noun-like concept. It also appears in various expressions and grammatical structures to express experiences, rules, and decisions.

What is the こと Nominalizer?

The word こと originally means “thing” or “matter,” but as a grammatical tool, it turns actions (verbs) and ideas into abstract concepts, making them function as nouns.

Example of Nominalization with こと

日本語を勉強することは楽しいです。 
(Nihongo o benkyou suru koto wa tanoshii desu.)
"Studying Japanese is fun."

In this sentence:

日本語を勉強する (Nihongo o benkyou suru) = “To study Japanese” (verb phrase)
こと (koto) = Turns the verb phrase into a noun-like structure
は (wa) = Topic marker
楽しい (tanoshii) = “Fun”

Here, こと allows us to treat “studying Japanese” as a general concept rather than a specific action.

How こと Nominalizes Verbs and Adjectives

Turning Verbs into Nouns with こと

When こと follows a verb (in its dictionary form or past tense), it transforms the verb into a noun phrase that can act as a subject or object in a sentence.

歌うことが好きです。 
(Utau koto ga suki desu.)
"I like singing."

歌う (utau) = “To sing”
こと (koto) = Turns “to sing” into “singing” (noun phrase)
が (ga) = Subject marker
好き (suki) = “Like”

Turning Adjectives into Nouns with こと

While こと primarily works with verbs, it can also be used with な-adjectives and certain い-adjectives to turn them into noun-like concepts.

大切なことを忘れないでください。 
(Taisetsu na koto o wasurenaide kudasai.)
"Please don’t forget the important things."

Here, 大切な (taisetsu na) = “Important,” and こと allows it to refer to “important matters” in general.

Common Sentence Structures with こと

Expressing Likes and Dislikes

✅ 旅行することが好きです。 (Ryokou suru koto ga suki desu.)
➡ "I like traveling."

✅ 勉強することが嫌いです。 (Benkyou suru koto ga kirai desu.)
➡ "I dislike studying."

Expressing Abilities (ことができる)

日本語を話すことができます。 
(Nihongo o hanasu koto ga dekimasu.)
"I can speak Japanese."

The structure ことができる means “to be able to do something.”

Expressing Necessity (ことが必要 / ことが大事)

もっと練習することが必要です。 
(Motto renshuu suru koto ga hitsuyou desu.)
"Practicing more is necessary."

健康を守ることが大事です。 
(Kenko o mamoru koto ga daiji desu.)
"Protecting your health is important."

These expressions are common in formal writing or advice-giving.

Expressing Rules and Customs (ことになっている)

この会社では、毎朝掃除することになっています。 
(Kono kaisha de wa, maiasa souji suru koto ni natteimasu.)
"In this company, it is customary to clean every morning."

ことになっている is used to express rules, traditions, or social customs.

Expressing Decisions and Plans (ことにする / ことになる)

私は毎日運動することにしました。 
(Watashi wa mainichi undou suru koto ni shimashita.)
"I decided to exercise every day."

会議は午後3時に始まることになりました。 
(Kaigi wa gogo sanji ni hajimaru koto ni narimashita.)
"It has been decided that the meeting will start at 3 PM."

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