時
When, At the time of
Structure
［い］Adjective + とき
［な］Adjective + な + とき
Noun + の + とき
Explanation
とき, written in kanji as 時, is a noun used to express 'when' an action takes place. Unlike other time-related words, とき is typically used for things that occur regularly (like habits or routines) or during broader timeframes or specific occasions (e.g., when it is cold, when I go to the store).
Using とき is straightforward. It attaches to the end of a word, such as a verb, noun, or adjective. Following standard Japanese grammar rules, な-Adjectives require な before とき, and nouns require の. The particle に will often appear right after 時 to indicate the time at which the following action occurs.
- 夕飯を作っていたときに警報器が鳴った。The alarm went off when I was making dinner. (Individual event)
- 寒い時はセーターを着ます。When it's cold, I wear a sweater. (Broad time)
- 彼女は暇なときに音楽を聴きます。She listens to music when she has free time. (Hobby)
- 休日の時はジムに行きます。When it's my day off, I go to the gym. (Habit)
Caution
As mentioned, ときに is used to mark the time an action occurred. It is not used to simply state a fact that was true at the time of another action. For instance, you wouldn't use it to say 'the day I ate that was my birthday'.
- ケーキを食べた時に誕生日だった。The time when I ate the cake was my birthday. (Being your birthday is a state, not an action, so とき is not used this way.) (Unnatural Japanese)
When とき is used correctly, it creates the nuance that one event occurs during another, or that one action leads to a subsequent one.
- 私は大学生の時にコンビニでアルバイトをして、色々な人に会った。When I was a university student, I worked part-time at a convenience store and met all sorts of people. (時 establishes the broad timeframe of 'being a university student', and the rest of the sentence describes experiences that happened during that period.)
Examples
料理をするとき、エプロンをつけます。
I wear an apron when I cook.
会議のときは携帯電話の電源を切ってください。
Please turn off your cell phone when you're in a meeting.
子どもが生まれたとき、とてもうれしかった。
When my child was born, I was very happy.
暇なときは、本を読んだりゲームをしたりします。
When I have free time, I do things like read books and play games.
眠いときは、コーヒーを飲む。
When I'm sleepy, I drink coffee.
日本に来たときに、初めて寿司を食べた。
When I came to Japan, I ate sushi for the first time.
図書館で本を借りるとき、カードが必要です。
You need a card when you borrow books from the library.
家に帰るときは、「ただいま」と言います。
When you return home, you say 'ただいま' (I'm home!).
大学に合格したとき、家族みんなでお祝いをした。
When I got accepted into university, my whole family celebrated.
寝るとき、必ず電気を消します。
I always turn off the lights when I go to sleep.
道に迷ったとき、交番で道を聞いた。
When I got lost, I asked for directions at a police box.
駅に着いたとき、電車はもう出てしまった。
When I arrived at the station, the train had already left.