Their shows possession
Use their to show that something belongs to or is associated with a group of people. Example: “Their car is outside.”
There refers to a place or introduces a phrase
Use there for a location, as in “Put it there,” or in constructions such as “There are two options.”
They're means they are
They're is a contraction. Expand it to “they are” to check the sentence. Example: “They're ready” means “They are ready.”
Frequently asked questions
Is “their going home” correct?
Not when you mean “they are going home.” The correct form is “they're going home.”
How do I remember them?
Their relates to ownership, there points to a place, and they're can be expanded to they are.