This is the name of a structure we use in English to explain a sentence that starts as a statement and is turned into a question. For example the sentence: You take 2 sugars, don’t you? At the start of the sentence we form a sentence structure (you take 2 sugars), and then the sentence is turned into a question that needs a response (don’t you?)
It generally gets called Question tags by British English speakers and Tag questions by American English speakers.
Many languages have the concept of question tags, so most of your students will get the idea quickly. In most cases, a Question tag is used in informal spoken language, and is rarely used in written English.
There are many reasons to use a question tag. One of the main reasons is when we genuinely think we know something, but are not completely sure, so we would like confirmation. For example:
You take 2 sugars, don’t you? (As I remember, you take sugar in coffee but I’m not 100% sure, so I want confirmation).
Studies show people who lack confidence generally use them a lot. There are also some regions in the UK where Question tags are used as a habit. Think about it: it can also help us tease someone, be aggressive or ironic.
Professional question tags are used a lot by salesperson. If you have said yes 4 times, and I ask you to buy it, psychology suggests it’s difficult for you to say no. For example:
Sales man: So you said you really loved the colour of the car, didn’t you?
Sales man: And the boot is big enough for your Golf clubs, isn’t it?
Sales man: It is the kind of a car you were looking for, weren’t you?
Sales man: It’s more or less in your price range, isn’t it?
Sales man:Okay, will you be buying in cash or will you need credit? (it’s difficult for the customer to say anything negative when he has said yes so many times)
Another use of a question tag is in law. Often, we hear the term ‘leading question’ when we watch court room dramas. A leading question is often a question tag and it is normally not accepted by the court. For example: You were at the pub that night, weren’t you?
Generally, the rule for structure is that whatever auxiliary verb ( the auxiliary verb is what we call helper verbs such as the verb to be and model verbs) is the statement part of the sentence, we use the opposite form and the subject in the question part of the sentence that follows. For example:
you are late, aren’t you? ( are in the statement part of the sentence = aren’t in the question part)
you won’t be late, will you? ( won’t in the statement part of sentence = will in the question part)
Now you understand the main principle, you should be able to apply it to all the other auxiliary verbs, even with varying tenses. Here are some examples that show some of the auxiliary verbs and some of the tenses being used:
He should read this book, shouldn’t he?
He isn’t reading the book, is he?
She couldn’t read the book, could she?
They won’t read the book, will they?
You have read the book, haven’t you?
The children are not allowed to read the book, are they?
She was reading the book, wasn’t she?
You must read the book, mustn’t you?
She couldn’t have read the book, could she?
We can read the book, can’t we?
Sometimes our main sentence, our statement, doesn’t have an auxiliary verb and we still want to make it into a Question tag. In such cases, we add the auxiliary verb do. We also need to remember to use the correct version, depending on what tense we need the sentence to be in and whether the question is negative or positive.
You like reading, don’t you?
He likes reading, doesn’t he?
You don’t like reading, do you?
He doesn’t like reading, does he?
You didn’t read the book, did you?
You read the book, didn’t you?
Note: These are the rules for Question tags, but you will find that many different regions of the UK either use questions tags for no reason whatsoever and other areas, for example inner city or very urban areas, use them incorrectly. For example. He has the car, innit? (isn’t it). Although there is no reason to teach these variations, you may have to make your higher level students aware of the possibility in certain tasks, such as listening tasks.