Student or Learner
When asking, is there any rule to follow when using What or Which?
What's correct? "What is the meaning?" or "Which is the meaning?" and why?
When do we use What and when Which?
Thanks a lot
What versus which
What is used when specific information is requested from a general or open-ended possible range. Which is used when specific information is requested from a restricted range of possibilities:
A: Iíve got your address. Whatís your phone number?
B: Oh itís 267358.
(NOT Which is your phone number?)
(an open-ended range of possible information)
[looking at a pile of coats]
A: Which is your coat?
B: That black one.
However, where the number of options is shared knowledge among speakers and listeners, what + noun is often used in informal contexts. Here, what is an interrogative pronoun used as a determiner:
[talking about a shop]
What side of the street is it on, left or right?
(or: Which side of the street is it on?)
A: Did you see that documentary about the SARS virus last night?
B: No, what channel was it on?
(or: Which channel was it on?)
by Cambridge Grammar of English, 2006