If a girl keeps being annoying?

Well the next time she's annoying to you, politely ask her to stop, if this carries on say something like "I said can you please stop, are you having difficulty working out what that means?" If she STILL carries on just tell a teacher, then she will most likely stop, if she doesn't then just laugh at everything she's saying (not laughing at her comments laughing at how pathetic she is) Then if she is driving you mad don't ever say shutup or anything like that, because most of the time, that will make things worse, that's what she wants you to do, so to really annoy her, completely BLANK her out, pretend she's not there and ignore everything she's saying, that will really annoy her because she wants you to retaliate, so eventually she will get bored of you and stop. (If you are a boy she probably has a crush on you and is trying to get your attention)