They are extremely tricky to get down in any new language. I've just bought a guide to Italian prepositions, and in it I have discovered that, depending upon the context, the following translations of Italian prepositions into English are possible (and this is at a minimum -- I assume there are possibilities I have not yet discovered):   a  --> with, by, at, to, because, per   di  --> at, by, from, in, around, of, with   da  --> from, to, because of, for, as, by, with   in  --> after, at, in, inwards, from, on, to   per --> for, through, to, by, because, because of   su  --> about, around, in, on, up, upward   tra --> amid, among, between, for, in, of   Ooh boy.