GRAMMAR DETAIL

～とき

when · at the time of

Indicates the time when the event in the following clause occurs.

Examples

子どものとき、この川でよく遊んだ。

When I was a child, I often played in this river.

道に迷ったときは、この番号に電話してください。

If you get lost, please call this number.

Structure: Modify とき with a verb, adjective, or noun to give the time setting of the following event.
Basic usage: 子どものとき、この川でよく遊んだ。 places the activity of playing in childhood.

Nouns and adjectives
- A noun takes の in 子どものとき, and a na-adjective takes な in 暇なとき. An i-adjective connects directly, as in 寒いとき.
Completion in the clause and overall time
- 迷ったときは電話してください can refer to a future occasion of getting lost. 迷った sets the reference point after becoming lost, rather than making the whole sentence past tense.