MIND THE TRAP!
 
1)  
‘s = isShe’s a doctor, isn’t she?
‘s = hasShe’s got a new car, hasn’t she?
‘s = usLet’s play volleyball, shall we?
‘d = hadAndy’d written before you phoned, hadn’t he?
‘d = wouldThese girls’d rather go by air, wouldn’t they?

2)
statement
tag
 example
I amaren’t I?I’m late, aren’t I?
Imperative (+)will/won’t you?
can you/could you?
Please help me, won’t you?
Imperative (-)will you?Don’t speak, will you?
Let’s = let us shall we?Let’s play computer games, shall we?
Let me/him/her/themwill/won’t you?Let her do it, won’t you?
There is
There are
isn’t there?
aren’t there?
There are some tickets left, aren’t there?
This is/That isisn’t it?This is your bag, isn’t it?
(I) have + V3
(he) has + V3
haven’t (I)?
hasn’t (he)?
They have got a house, haven’t they?
He has gone to London, hasn’t he?
(I) have
(he) has 
don’t (I)?
doesn’t (he)? 
You have dinner every day, don’t you?
He has to wear a uniform, doesn’t he?