Me Again! Miss Grammar! Ready? Oooooh Kaaaayy!
They're / There / Their
They're = a contraction of "They are."
For example: They're going to the mall. They're a happy couple. They're in the house.
Whenever you can say "They are," you can use "They're."
There = a location. In or at that place or position.
For example: We are going there tomorrow. There once was a man from Nantucket. I put the keys right there! There should be a law against pants so low, you can see your underwear!
Their - Belonging to them.
For example: Their house is beautiful. Their son made the All-County Choir (wh00t! Go Jake). I think their objections are ridiculous.
Let me wrap it up for you. Ready?
Their daughter thinks they're crazy to go there after dark.
Thank you, thankyouverymuch.