I'm frustrated! One of my biggest pet-peeves is reading something in which the three words "their", "there", and "they're" are mis-used or substituted for one another. I just finished reading a post in which "their" was used for every instance of "their", "there", and "they're", and I had to stop reading for a while. When I read a sentence like "Their is a mistake in this sentence.", I want to stop and correct it. I know it sounds like I'm being too picky, but it's just something that gets to me. So here's a quick crash course on when & how to use these three wonderful dramatic and oh-so-misused words: They're - conjunction of "they" and "are". i.e. "They're going to have to learn to spell properly so that Moe's head doesn't explode". Their - posessive form of "they". i.e. "Their misuse of these three words is going to make Moe's head explode". There - NO relation to "their" or "they're", and used to refer to a subject. i.e. "There is Moe, his head has just exploded". Moe. Edit: corrected my own silly spelling mistake, as many have ironically pointed out to me.