What comes first ?

[Nugpacious]

I know a chap who has adopted a style of grammar "of which I am curious".

Commonly, someone might say, "I'll see you next week, at the movie premiere that we've been waiting for."

However, this gentleman instead says, "I'll see you next week, at the movie premiere for which we've been waiting."

My questions are:

(1) What exactly is happening here, from a grammatical standpoint ?

(2) Is one of these forms more proper than the other ?

(3) Where can I go to learn more about how to use this technique in other instances ?

Thanks

[Alan]

He is simply using a more formal sentence-pattern that is more typical of written than of spoken English, in which the preposition (here 'for') precedes its object relative pronoun (which) rather than being placed at the end of the clause.