What it means
とき means “when” or “at the time of.” It connects a time or situation to an action or event. The part before とき describes the situation or time, and the main clause describes what happens then. The form of the preceding verb can show whether the action happens before or after the main event.
Usage note
With a noun, use のとき, and with a na-adjective, use なとき. With a verb, the dictionary form usually describes an action that has not happened yet or is in progress, while the past form describes an action that has already happened. The clause before とき normally uses a plain form even when the main sentence is polite.
How to use it
私は学生のとき、京都に住んでいました。
When I was a student, I lived in Kyoto.
元気なとき、毎朝走りました。
When I was energetic, I ran every morning.
忙しいとき、本を読みません。
When I am busy, I do not read books.
家へ帰るとき、母に電話します。
When I go home, I call my mother.
家へ帰ったとき、母に電話しました。
When I returned home, I called my mother.
私は学生のとき、京都に住んでいた。
When I was a student, I lived in Kyoto.
元気なとき、毎朝走った。
When I was energetic, I ran every morning.
忙しいとき、本を読まない。
When I am busy, I do not read books.
家へ帰るとき、母に電話する。
When I go home, I call my mother.
家へ帰ったとき、母に電話した。
When I returned home, I called my mother.
Example sentences
駅へ行くとき、傘を持っていきます。
When I go to the station, I take an umbrella with me.
図書館で本を借りたとき、返す日を確認しました。
When I borrowed a book at the library, I checked the return date.
料理をするとき、手をよく洗います。
When I cook, I wash my hands well.
眠