Another pet peeve of mine, unsurprisingly, is when people use the wrong ‘there’ in a sentence. You can see it ALL THE FREAKING TIME on facebook and twitter (not so much on Google+, mainly I think because early adopters are not complete idiots).
And yes, I KNOW it makes me a pedantic, pretentious dick to really care about it, but when someone I know uses the wrong ‘there’, it makes me feel like I don’t want to know them anymore because they are an idiot.
Of course I make exceptions for non-native english speakers, but if you speak primarily english and use the wrong ‘there’ in a sentence. You are an idiot.
In pursuit of the goal to have less idiots in the world, in plain english, here’s my small contribution:
“There” generally indicates a position, location or declaration… “I put the book over there”, “Jack and Jill went there on holiday”, “There is only one syllable in the name ‘Bob’”.
"Their" is posessive… “I read their new book”, “Jack and Jill took their holiday in Spain”, “Their names are Jack and Jill”.
“They’re” is simply short for ‘they are’… “They’re writing another book at the moment”, “They’re going on holiday to Spain”, “Oh Jack and Jill? They’re great!”
So EVEN if it’s just facebook please, for my sake and yours; try to use the right their, there or they’re on there or they’re going to think you’re an idiot :)