A question tag is a grammatical structure in which a statement or an imperative is turned into a question, by adding an interrogative fragment (the "tag") at its end.
Most of the times you're not really asking because you really know the answer already. You're just making sure that it is the answer you expect.
As in the example on the photo:
This is a tag question, isn't it?
(It is a tag question, you only want to make sure that it is).
This is how they work:
The statement can be affirmative or negative, the question tag is in the opposite: if affirmative statement, negative tag and viceversa: if negative statement, affirmative tag. Always use the corresponding personal pronoun in a question tag.
To make the correct question tag, you must always use the corresponding auxiliary verb according to the statement, this depends on the statement's verb tense form or if a modal verb is used. Look at the examples below:
- Simple tenses will use DO.
- Continuous tenses will use BE.
- Perfect tenses will use HAVE.
- with modal verbs, the same modal verb is used.