when
//wɛn//
Adverb
1
At what time; used to ask about the time at which something happens or happened.
When does the train arrive?
2
At or during the time that; used to refer to the time at which something happens.
I was sleeping when you called.
Conjunction
1
At or during the time that; while.
I always listen to music when I study.
2
At any time that; whenever.
When I'm tired, I drink coffee.
3
Considering that; although; whereas.
Why do you want more money when you already have so much?
Pronoun
1
What time; which time.
Since when have you been living here?
Noun
1
The time at which something happens.
We need to decide on the when and where of the meeting.