Tag Questions

Question Tags – Advanced Points

The question tag for I am is aren’t I?
I am late, aren’t I? (NOT …amn’t I?)

Imperatives can be followed by will you / would you / can you / can’t you / could you?
Keep quiet, can’t you?
Give me a hand, would you?
Open a window, will you?

After a negative imperative, we use will you?
Don’t forget, will you?

The question tag for let’s is shall we?
Let’s go for a walk, shall we?

Negative words
Sentences containing negative words like never, no, nobody, hardly, scarcely and little are followed by non-negative question tags.
You never let me finish a sentence, do you? (NOT …don’t you?)
She hardly steps out of her home, does she?
There is little we can do about it, is there?

It is used in question tags to refer back to nothing and everything.
Everything is alright, isn’t it? (NOT …isn’t everything?)

We use they in question tags to refer to nobody, somebody, everybody, no one etc.
Nobody came, did they?

Somebody wanted a drink, didn’t they?


After have
When have is used as a principal verb, question tags with both have and do are possible in British English. Do is more common in American English.
She has a boyfriend, hasn’t / doesn’t she?

Notes
In sentences with question tags, pronoun subjects and auxiliary verbs are often left out.
Nice day, isn’t it. (More natural than ‘It’s a nice day, isn’t it?)

taken from:

http://www.englishgrammar.org/question-tags-advanced-points/