/ wen; NAmE / adverb , pronoun , conjunction
■ adverb
1.
(used in questions) at what time; on what occasion :
When did you last see him?
When can I see you?
When (= in what circumstances) would such a solution be possible?
2.
used after an expression of time to mean 'at which' or 'on which' :
Sunday is the only day when I can relax.
There are times when I wonder why I do this job.
3.
at which time; on which occasion :
The last time I went to Scotland was in May, when the weather was beautiful.
■ pronoun
what / which time :
Until when can you stay?
'I've got a new job.' 'Since when?'
■ conjunction
1.
at or during the time that :
I loved history when I was at school.
2.
after :
Call me when you've finished.
3.
at any time that; whenever :
Can you spare five minutes when it's convenient?
4.
just after which :
He had just drifted off to sleep when the phone rang.
5.
considering that :
How can they expect to learn anything when they never listen?
6.
although :
She claimed to be 18, when I know she's only 16.
•
IDIOMS
see as conjunction
••
WORD ORIGIN
Old English hwanne , hwenne ; of Germanic origin; related to German wenn if, wann when.