Yeah it bothers me too. It's not as easy as @movies@lemmy.world suggests though, I think. Yes, apostrophe means you're using a contraction, so "it's" should be easy.

But apostrophe also means possession in almost every other case. "It's" and "there's" are literally the only examples I can think of in standard English where an apostrophe can be used, but cannot mean possession. Native speakers still have no excuse, but it is a bit of a weird oddity that has to be learnt.

What really bug's me is when people randomly throw apostrophe's in where they just make no sense, on what should be simple plural word's or even just verb conjugation's. And it happen's all the damn time. (I'm so sorry.)