Its/It’s, Their/They’re/There

The key to a lot of mix-ups like these is that these words all fall into categories that include lots of other words formed exactly the same way. So you can remember the right word by thinking about the other words in the same group.

Just sharing with you what helped me:

its	is possessive	The word is patterned like other possessives like it:   The state government in Albany has lost its credibility.	yours, his, hers, its
it’s	= it is	The word is patterned like other contractions:   It’s time to think about taxing goat cheese.	I’m, you’re, he’s, she’s, it’s
their	is possessive	The word is patterned like other possessives like it:   I like the Martians, but, boy, their spaceships sure are ugly.	our, your, their
they’re	= they are	The word is patterned like other contractions:   The Ravenclaws aren’t coming. They’re going to Fred’s party instead!	we’re, you’re, they’re
there	is a location	The word is patterned like other pointing terms:   I’ve always wanted to visit the planet Skaro, but I’ve never actually been there.	here, there, everywhere