What’s the difference between their, there, and they’re? They’re really not that complicated; once you understand their differences, there shouldn’t be any more confusion.
Their is the third person plural possessive adjective, used to describe something as belong to them. Their is nearly always followed by a noun.
Where is their car?
Are these their pens?
Their books are on the table.
This is their room and this is ours.
What happened to their dog?
Their being here is causing some problems.
There has several different uses.
1. Adverb that means the opposite of "here"
He’s over there.
Stop right there.
Do you want to sit here or there?
2. Pronoun that introduces a noun or clause.
There is something strange going on.
Is there a phone?
3. Adjective that emphasizes which person.
That guy there seems to be in trouble.
Those there look good.
4. Noun that means "that place."
From there, we drove to Boston.
I’m not going in there.
They’re is the contraction of "they are" and is often followed by the present participle (verb form ending in -ing).
They’re going to be late.
Is that what they’re saying?
I think they’re lying.
If they’re ready, we can go.
I can’t believe they’re not here yet!
When they’re older, they’ll understand.
The Bottom Line
The confusion between their, there, and they’re occurs because the three words are pronounced in very similar ways.
If the word means "belonging to them," use their. If you’re able to replace the word with "they are," use they’re. Otherwise, there is only one correct answer: there.