ive always had trouble with this. when do you write whom and when do you write who? whats the difference?
google 'who vs whom' for chapter and verse on usage... google is always quicker and turns up more reliable info for things like this...
Technically, 'who' is the subject pronoun and 'whom' is the object pronoun, but you can use both really, it just depends how formal you want your English to be. e.g. Who are you speaking to? To whom are you speaking? (formal, fast becoming archaic style). Sometimes I want a character to speak in a lah-di-dah way, for example, and I would use 'whom'. Google, as maia suggests, for the nitty-gritty.
I rarely use 'whom' - I know the grammatical useage, but like Madhoca says, it comes across as either archaic or posh and preppy. If I did use it, I would always put it after the prepostion, as in 'for whom the bell tolls' or 'with whom did you dance at the ball?' That sentence structure in itself marks the speaker as rather well to do or old fashioned, as the old rule of putting the prepositional phrase first to avoid a sentence ending with a preposition is dying out. Nowadays, using 'who' as an object noun and ending sentences with a preposition is commonplace and almost universally accepted. Most of the time I'd write 'who did you dance with?'
