Meaning of when in English
Conjunction
1. at or during the time that; at the moment that
I will see you when I return.
When the teacher opened the door, the pupils stopped playing and laughing at once.
3. after
Can I borrow that book when you've finished it.
4. although
The waiter brought me beer, when I had asked for whisky.
What am I to do when she refuses?
You can come to talk to me when you are in trouble.
Die when you will, I will with you.
8. since
I cannot go when I haven't been invited.
Interrogative adverb
When do you get up? ー What time do you get up?
Interrogative pronoun
1. used to ask about the time of an event etc.
"When is your birthday?" "It's March 26."
1. ⦅in restrictive use⦆ at or on which
I don't know the time when she will arrive.
2. ⦅in non-restrictive use⦆ at that moment; and just then; and then
I saw her in July, when she was in Australia.