Part 1: ～とき (When / At the time of ~)
Emphasizes the time an event occurs or an action is performed.
Specifically for verbs:
When using とき, the verb before it (V1) is conjugated based on the sequence of actions.
* V1た: V2 happens after V1 (V1 occurs first).
* V1る: V2 happens before V1 (V1 occurs later).
→ ① When (after) I leave the room, I close the door. (The verb 出た is in the past tense, indicating leaving the room happens first.)
→ ② Yesterday, when (before) I returned home, I bought some bread. (The verb 帰る is in the present/future tense, indicating buying bread happens first.)
→ ③ I put sugar in when I drink coffee.
B: アイスクリームを食べたとき、歯がいたくなりました。
→ ④ A: Grandma, what's wrong? B: My teeth started to hurt when I ate ice cream.
→ ⑤ When you are sick, you must take medicine.
Part 2: ～と
Used for obvious facts or inevitable results following an action.
The clause following と cannot express the speaker's volition (
→ ① When I drink alcohol, my head hurts.
B: このつまみを右へ回すと、音が大きくなりますよ。
→ ② A: Excuse me, the volume is a bit low. B: If you turn this knob to the right, the volume will increase.
B: このみちをまっすぐ行って、あの角を左へ曲がると、花屋は右にありますよ。
→ ③ A: Excuse me, where is the flower shop? B: If you go straight down this street and turn left at that corner, the flower shop will be on your right.
Part 3: ～を
Indicates the spatial area through or across which a person or thing moves.
V is a verb of motion or direction (
→ ① Take a walk in the park.
→ ② Cross the street.
