which

which

W1S1 [wıtʃ] determiner, pron

[: Old English; Origin: hwilc]

1.) used to ask or talk about one or more members of a group of people or things, when you are uncertain about it or about them

▪ Which book are you looking for?

▪ Which are the most important crops?

▪ Miranda was sure it was one of them, but was not sure which.

which of

▪ I don't know which of us was the more scared.

2.) used after a noun to show what thing or things you mean

▪ Did you see the letter which came today?

▪ Now they were driving by the houses which Andy had described.

3.) used, after a ↑comma in writing, to add more information about the thing, situation, or event you have just mentioned

▪ The house, which was completed in 1856, was famous for its huge marble staircase.

▪ One of the boys kept laughing, which annoyed Jane intensely.

▪ He was educated at the local grammar school, after which he went on to Cambridge.

▪ She may have missed the train, in which case (=if this happens) she won't arrive for another hour.

4.) don't know/can't tell etc which is which

if you do not know which is which, you cannot see the difference between two very similar people or things

▪ The twins are so alike I can never tell which is which.

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HINT sense 2

In informal and spoken English, it is more usual to use that : This is the one that I wanted.

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