which
//wɪtʃ//
Determiner
1
Used to ask for information specifying one or more people or things from a definite set.
Which color do you like?
2
Used to refer to something previously mentioned when introducing additional information about it.
She gave me a book, which was very interesting.
Synonym
Pronoun
1
Used to ask for information specifying one or more people or things from a definite set.
Which do you want, tea or coffee?
2
Used as a relative pronoun to introduce a clause giving further information about something previously mentioned.
I bought a book, which was very interesting.