which
which
/wɪtʃ/
1 used in questions to ask somebody to be exact about one or more people or things from a limited number
Which is better exercise—swimming or tennis?
Which way is the wind blowing?
Use a singular verb after which if only one person or thing is meant; use a plural verb if it is more than one: Which of the applicants has got the job? (= Although there was more than one applicant, I know that only one has got the job.) • Which of the patients have recovered? (= It is possible that more than one patient has recovered.)
2 used to be exact about the thing or things that you mean
Houses which overlook the lake cost more.
It was a crisis for which she was totally unprepared.
That can be used instead of which in this meaning, but it is not used immediately after a preposition. It was a crisis that she was totally unprepared for. • It was a crisis for that she was totally unprepared.
3 used to give more information about something
His best movie, which won several awards, was about the life of Gandhi.
Your claim ought to succeed, in which case the damages will be substantial.
That cannot be used instead of which in this meaning.
Idioms
Word Origin
Old English hwilc, from the Germanic bases of who and alike.