I've been doing a fair amount of "grammar" study lately, partly just to refresh myself and partly for an article I'm working on. Last night I was reading up on prepositions, and I thought I'd post a bit here about them. (BTW, thanks to everyone for their comments on my "tense" post. It was a very helpful discussion.)
Prepositions are words such as “in,” “to,” “with,” “at,” “for,” “from,” “upon,” “among,” “between,” “behind,” and “about.” They indicate the relationship between a noun or pronoun and some other word in the sentence. He undressed behind the hedge is an example of this usage. “He undressed” is connected to “hedge” by “behind.”
It is a common belief, but a wrong one, that a writer should never end a sentence with a preposition. The most likely reason for the belief is that in casual speech people often add an unnecessary preposition to the end of a sentence. Where should we go to, or, Where have you been at are examples of this. The prepositions, “to” and “at” are not needed here. But, what movie are you going to is perfectly fine. The “to” is necessary and putting it at the end saves you from such obfuscating constructions as "what movie is it to which you are going."