Question Tags
Question tags are short questions added to the end of a statement to ask for agreement or confirmation.
The Basic Rule
If the main sentence is positive, the tag is negative. If the main sentence is negative, the tag is positive.
It's a beautiful day, isn't it? You don't like coffee, do you?
Auxiliary Verbs
Use the same auxiliary verb as the main sentence. If there is no auxiliary, use do/does/did.
She can speak French, can't she? They arrived yesterday, didn't they?
Exceptions
I am > aren't I? (I am late, aren't I?)
Let's > shall we? (Let's go, shall we?)