To vs Too
To is relating to an action.
I want TO swim.
(Also, in addition to, etc.)
I don't like that TOO well.
And then there is... There/Their/They're.
If in doubt- ask yourself these questions:
#1. If I say "They are" in place of "there/their/they're" does it work?
They are going to the mall. (passes test)
That is they are mall. (doesn't pass test)
If it doesn't pass the first question.. ask the next...
#2. Does it belong to them? Is it posessive?
That is there opinion. (incorrect)
If it can't be they're because "they are" makes no sense, and it isn't possessive, then it is there.
There is location. Think "here" and t"here".