Part 3 · Joining ideas · Lesson 24
の and こと: turning a clause into a noun
How Japanese makes a verb or a whole clause into a thing you can talk about: 'reading is fun', 'the fact that he left', 'I've been there', 'I decided to...'. And how to choose between の and こと.
Sometimes you want to treat an action as a thing: "Reading is fun", "I like swimming", "I forgot that I had class today". English has "-ing" and "that". Japanese uses two small words, の and こと, which turn a clause into a noun.
The basic move
Put a clause in plain form, then add の or こと:
From here the clause behaves like any noun, so it can take particles: は, が, を, に, で.
の or こと?
They overlap, but not entirely. Roughly:
| Use の when... | Use こと when... |
|---|---|
| you see, hear or feel it directly | it's an abstract idea or a fact |
| the verb is about perception: 見る, 聞く, 手伝う, 待つ | the verb is about knowing or doing: 知る, 忘れる, 言う |
| the speech is casual | the speech is formal or written |
Several fixed expressions require one or the other. In these, you can't swap:
| Pattern | Meaning | Example |
|---|---|---|
| 〜ことがある | there are times when; have done | 行ったことがある |
| 〜ことができる | can do | 泳ぐことができる |
| 〜ことにする | decide to | 行くことにする |
| 〜ことになる | it's been decided / it turns out | 行くことになる |
| 〜ことだ | you should | 早く寝ることだ |
You need not memorise these now. Remember the pair: の for perception and casual use, こと for facts and fixed phrases.
ことがある: experience
Past plain form + ことがある = "have done" (have had the experience of).
The same pattern with the dictionary form, ことがある, means "it sometimes happens that...":
ことにする: decide to
ことになる: it's been decided, it has come about
This is the "it ended up that..." or "it has been arranged that..." pattern. It's about outcomes that were not entirely your own choice, or are presented as such (a company announcing a decision, for example).
ようになる: become able to / come to
Verb + ようになる means a change in ability or habit: "come to do".
Its negative is ようにならない / なくなった.
The explaining の: のだ / んです
Back to the final の you met earlier. Combined with だ / です, it makes a sentence that gives a reason or explanation or asks for one.
The pattern is plain form + のだ (or んだ / んです in speech). It says "here's the explanation / the situation is that...". Learners sometimes see んです as a mystery; think of it as the "because" voice, used to explain or to request an explanation. We cover it more in the lesson on reading real Japanese.
Longer sentences
Nominalized clauses can be subjects, objects, topics and more. Look for の and こと as the end of a clause-noun.
An argument made of nominalized clauses
Key points
- の and こと turn a clause into a noun: 読むの, 読むこと.
- の for perception and casual; こと for facts and set phrases.
- 〜たことがある (have done); 〜ことにする (decide); 〜ことになる (it's been decided); 〜ようになる (come to).
- のだ / んです explains or asks for an explanation.
Drill these patterns
Short example sentences for the points in this lesson: