Grammatically Correct

I am not a grammar nazi. I do not go around correcting everyones spelling and grammar. I do to my aunt because she annoys me with her spelling mistakes. 'Kool'. Excuse me, it's 'cool'. I am not trying to annoy people, I am helping them ;) if they write a letter to someone important and write incorrectly, the wrong type of 'your' and 'you're', for example, then the person of whom they are writing to is not going to take them correctly. It just pisses me off.