in which, to which, at which..all about which..

[micmicmic]

could anyone explain me how to use these properly ? i know sometimes in which is equivalent to where, when.. but actually i have no idea..

thanks in advance!

[rewboss]

Take these two sentences:

This is the house. Jack built it.

Now, if we wrote English like that all the time, it would sound like a book for very young children who are learning to read. We can combine these sentences using a relative clause:

This is the which Jack built.

OK, that's easy enough: but how do we combine these two sentences?

This is the house. Jack lives in it.

We can't simply say: "This is the house which Jack lives." It doesn't make sense -- we need to fit in the sense of "in". That little preposition mustn't be allowed to disappear.

There are two ways of doing this: the traditionalist and the modern. The modern way is just to leave "in" at the end of the sentence, like this:

This is the house which Jack lives in.

We don't need "it" any more, because that is included in the relative pronoun "which". But many people object that putting a preposition at the end of a sentence like this is wrong, so for formal English you're better off using the traditionalist approach, which is to put the preposition in front of the relative pronoun, like this:

This is the house in which Jack lives.

So no, "in which" is not an equivalent to "which". You can do the same with many other prepositions, e.g.:

This is the school. Jack goes to it.
-> This is the school to which Jack goes.

This is the disco. Jack met his girlfriend at it.
-> This is the disco at which Jack met his girlfriend.

This is the house. There is a long nursery-rhyme about it.
-> This is the house about which there is a long nursery-rhyme.

[micmicmic]

Thank you, i think i got it. But i'd love to know more about the actual meaning for in which.. etc

maybe what i need is just some more examples! :)

thanks