Study materials
Ukrainian has one word for this in every case. In English the tail is different each time, because it repeats what is already in the sentence.
It is cold, isn't it?
They can swim, can't they?
Leo works here, doesn't he?
A tag is not invented. It is assembled from the sentence itself in three steps.
Three steps
Here is the whole mechanism. Take the steps in order and the tag builds itself.
| Step | What to do |
|---|---|
| 1 | find the helper: be, have, can, will and the like |
| 2 | flip the polarity: positive becomes negative |
| 3 | replace the subject with a pronoun |
She has arrived, hasn't she?
It isn't cold, is it?
If the sentence has no helper, as in the Present or Past Simple, one is called in: do, does or did.
You came by car, didn't you?
A few forms to learn separately
Three cases do not follow from the rule, so they are simply memorised.
I am late, aren't I?
Let's go, shall we?
Close the door, will you?
Hidden negatives
The words never, nobody, nothing, hardly and seldom carry no not, yet they are negative in meaning. So their tag is positive.
Nobody called, did they?
She never complains, does she?
Note the pronoun in the first example. Nobody, everyone and somebody take they, even though one person is meant.
Intonation decides whether it is a question
The same tag can mean two different things. A rising voice is a real question: you do not know the answer. A falling voice is an invitation to agree: you are already sure.
You locked the door, didn't you?
That is why tags are so common in conversation: they draw the other person in without asking a direct question.
The mistakes everyone makes
The first is repeating the polarity instead of flipping it.
It is cold, is it? → It is cold, isn't it?
The second is taking the wrong helper.
She has arrived, doesn't she? → She has arrived, hasn't she?
The third is adding a negative where one is already hidden.
Nobody called, didn't they? → Nobody called, did they?
All three are caught by one look at the start of the sentence. What helper is there and what is its polarity? The tag simply mirrors it.
Try it right now
Make four English sentences with tags: one with be, one with a modal, one with no helper, and one with nobody or never.
Read the last one twice, with a rising and with a falling voice. Listen to how the meaning changes.