Japanese の and こと: Turning Clauses into Nouns
English often uses “-ing” or “that” for these ideas, but Japanese chooses の or こと based on the meaning and the expression around it. の often presents an event or activity as something concrete; こと often presents it more generally or appears in set expressions. A particle can follow either nominalizer, and the form before it changes with verbs, nouns, and adjectives.
The two nominalizers
A clause can take a particle
Put の or こと after a clause to make it noun-like so particles such as を, が, and は can follow; verbs inside these clauses use plain forms, and English “-ing” does not tell you which nominalizer to choose.
の is natural for directly perceived events, as in “兄が走っているのを見た”, and common with preferences and evaluations, as in “本を読むのが好きです”; こと often presents an activity more generally, as in “毎日歩くことは体にいい”, though these tendencies can overlap.
The established ability construction uses the dictionary form plus ことができます, as in “日本語を読むことができます”, and a decision to do something uses the dictionary form plus ことにする, as in “明日は歩くことにした”; both require こと rather than nominalizing の.
Before の, present affirmative noun and な-adjective clauses use な, as in “先生なの” and “きれいなの”; before こと, a noun uses である, as in “先生であること”, while a な-adjective can use な or the more formal である, as in “きれいなこと／きれいであること”.
An い-adjective attaches directly to either nominalizer, as in “いいの” and “いいこと”.
The examples marked informal use plain sentence endings such as 見た, した, and いい, suitable with friends and family, while those marked formal use polite endings such as です and できます, suitable with people you do not know well; here “formal” means polite speech, and neither the plain form inside the clause nor the choice of の or こと determines the whole sentence’s politeness.
- informal
兄が走っているのを見た。
- formal
本を読むのが好きです。
- informal
毎日歩くことは体にいい。
Use の for a directly perceived event
出来事を表す普通形の節のを見るの活用形。
- informal
兄が走っているのを見た。
Activities, preferences, and evaluations
活動や状況を表す普通形の節の主語・話題を示す助詞好みや評価の述語。
- formal
本を読むのが好きです。
- formal
この部屋がきれいなのはいいです。
Present an activity as a general topic
活動を表す普通形の節ことは評価の述語。
- informal
毎日歩くことは体にいい。
The established ability expression
動詞の辞書形で終わる節ことができます。
- formal
日本語を読むことができます。
The established decision expression
動詞の辞書形で終わる節ことにした。
- informal
明日は歩くことにした。
Forms before の and こと
Nominalizer の and possessive の
These two uses of の look alike but do different jobs. In “本を読むのが好きです。” (“I like reading.”), の follows the whole clause 本を読む and turns that activity into the thing marked by が. In “これは私の鞄です。” (“This is my bag.”), の connects 私 to the noun 鞄, showing whose bag it is; it does not turn a clause into a noun. English uses different forms here, so do not assume every Japanese の is possessive.
- formal
本を読むのが好きです。
- formal
これは私の鞄です。