Many people get confused by the three different spellings for these three words that sound exactly the same: their, there, and they’re. Here are the rules.
“Their” is a possessive, third person, plural adjective relating to “something belonging to them” – as in: their house, their political party, their stupid rules of grammar – and the entities involved have been named earlier, so it’s implied that you know who or what “they” are. What is being pointed out now is the house, party or rules “owned” by “them.” You can just as easily be talking about daffodils, with “their” flowers shimmering in the sun.
“There” has a few meanings. It can mean a physical place: over there, go there – or it can mean a virtual place: stop right there before you say something you’ll regret.
Sometimes “there” is used to express satisfaction, sympathy or even defiance:
There, it’s finished!
There, there, you’ll soon feel better.
There! You do it!
And “there” is frequently used to introduce a sentence or clause: “There comes a time…”
“Hi there” and “you, there” are sometimes used when we don’t remember someone’s name right away.
And let’s not forget They’re:
To confuse the issue even more, there’s a third usage that sounds the same but is spelled differently – “they’re.” Here the apostrophe indicates a missing letter. “They’re” is an abbreviation for “they are” – as in “they’re coming” or “they’re not so big.”