From a previous post, we can identify these three little words, there, their, they’re , as homophones – they sound the same but have different spellings and meanings.  But they are so easy to confuse, particularly if you are concentrating hard on the content of the writing!  So, a quick and basic reminder of how these are used:

They’re

This is a contraction of they are.

The word they is a pronoun in the same way that she is a pronoun.  A pronoun is a word that takes place of a noun.  (He, she, it, we, they for example).

They are becomes they’re and is generally pronounced the same as there and their.

Example:

Sammy and Jane are having a party tonight.  They’re inviting the whole street.

Tell me what they’re doing!

Be cautious when using this in writing:  this is a very common spoken form but take care when you are using it in writing.  Although contractions are increasingly common in formal writing, there is a time and a place to do so.  Be very aware of the audience that you are addressing.

There

Used as an adverb

Example:

(place)  On Tuesday, I went to the farm with my friends.   I met them there.

(point/case/idea) I disagree with you there.

Used as a pronoun

It is used with a verb especially to be.  The verb must agree with the true subject that follows.

Example:

There are some sweets left in the packet.

There is a dog in the room.

Their

Belonging to:

They were delighted when their dog won the show.

Their delight was obvious when their dog was awarded a prize.

For more information on there, their, they’re see  http://www.collinsdictionary.com/dictionary/english/there