Grammar › Time › とき
とき
"When…". It hangs off the end of a clause to mark the moment something happens — and the tense of the verb in front quietly says before or after.
The short version
Put a clause in front of とき (also written 時) to mean "when / at the time that". A verb before it stays in plain form; the tense of that verb tells you the timing relative to the main event.
食べるとき — when (about to) eat / while eating
食べたとき — when (I'd) eaten / after eating
Present-form verb + とき
A dictionary-form verb before とき frames the moment as still ongoing or just beginning — "when / while you do X".
で家を借りるときは。
And when you rent a place… (借りる — plain non-past)
私は環境が変わるとき。
For me, when my environment changes… (変わる — the change is the moment)
学校で給食を食べるとき。
When eating school lunch. (the timing of the action)
Past-form verb + とき
A た-form verb before とき means the action was already complete at that moment — "when (I had) X'd", "after X happened".
Watch out
The tense before とき sets the order. 行くとき「パスポートを買う」= buy it on the way (before arriving); 行ったとき「〜」= after you've arrived. The main sentence can still be past overall — the とき-clause carries its own relative timing.
🗣 Nouns and adjectives join with とき too. Use の after a noun (子供のとき, "when I was a kid"), な after a な-adjective (暇なとき, "when free"), and い-adjectives attach directly (忙しいとき, "when busy").
Next: まえに・てから — before / after → · 〜たことがある — have done → · All grammar
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