What are question tags?
These are structures that we add to the end of sentences. The tag turns a declaration or imperative statement into an interrogative.
Examples
Today is Wednesday, isn’t it?
They are over there, aren’t they?
This does change things, doesn’t it?
Why do we use question tags?
We use question tags for a number of reasons such as:
politeness – You have been working hard, haven’t you?
consensus – This is a good idea, isn’t it?
emphasis – That was not good, was it?
irony – That was clever, wasn’t it?
We may use question tags because we need reassurance
We did lock the door, didn’t we?
Maybe we are being confrontational
You are looking for trouble, aren’t you?
Or maybe defensive
You don’t really think I would do that, do you?
Question tags can require an answer or they can be rhetorical (don’t need an answer).
Which tag is used?
Unfortunately question tags are not generally interchangeable and there are some rules that need to be followed.
Question tags are constructed using an auxiliary verb and pronoun; the auxiliary verb must match the modality and aspect of the initial sentence:
You’ll throw that away when you have finished, won’t you?
They have decided to open on Sunday, haven’t they?
Note if we use the present perfect, the auxiliary needs to also use the present perfect.
It has been done, hasn’t it?
All of them had been changed, hadn’t they?
Helpful tip
Question tags always use the opposite of the initial clause:
You had noticed this already, hadn’t you?
You get the idea, don’t you? (sometimes we don’t repeat the verb)
You will not (won’t) forget this, will you?
Note that where we begin with a positive, the question tag is a negative (and vice versa).
Exceptions
When we use verb ‘be’ the question tag repeats the main verb rather than use an auxiliary:
This is the house, isn’t it?
Have you used any question tags today?
Are there any question tags you are unsure about?