I hadn't noticed the need to clarify these three different concepts until the day I handed out an exercise concerning them. For students that don't show many difficulties with English, this article might seem of no need, but for those that face English as a challenge, this might be of help.
Their is a pronoun like my, your, our... so you're saying that something concerns more than one person.
They're is the contracted form for they are, just like you have I'm, He's, She's instead of I am, He is, She is.
There is an adverb that means in that point in time or action.
Examples:
The girls' room is amazing! - Their room is amazing!
My parents are studying French now. - They're studying French now.
She is there in her room.
We went there last year.
Easy, right? :)
