At a glance
～とき means "when" or "at the time when". It links two clauses and tells you the time when the main action happens.
[Verb plain form / い-adj / な-adj + な / Noun + の] とき、[main clause]
暇なとき、本を読みます。 When I'm free, I read books.
How to form it
とき attaches to the plain form of the word before it. Politeness goes at the end of the main clause.
| Attaches to | Form | Example | Meaning |
|---|---|---|---|
| Verb (dictionary form) | 行く + とき | 行くとき | when (I) go |
| Verb (ない-form) | ない + とき | 時間がないとき | when (I) don't have time |
| Verb (た-form) | 行った + とき | 行ったとき | when (I) went |
| い-adjective | 忙しい + とき | 忙しいとき | when (I'm) busy |
| な-adjective | 暇 + な + とき | 暇なとき | when (I'm) free |
| Noun | 子ども + の + とき | 子どものとき | when (I was) a child |