Tag questions are used when seeking confirmation of what one believes to be true. They restate, in question form, the previously spoken sentence. For example,

He is an engineer. Isn’t he?

(Positive statement, negative tag)

They’re not from Colorado. Are they?

(Negative statement, positive tag)

Zack is really tired. Isn’t he?

(Positive statement, negative tag)

She is going to Taiwan, isn’t she?

(Positive statement, negative tag)

You have never been to Las Vegas. Have you?

(Negative statement, positive tag)

The Rays are playing the Jays. Aren’t they?

(Positive statement, negative tag)

You went to the supermarket. Didn’t you?

(Positive statement, negative tag)

Zane doesn’t live in Missouri. Does he?

(Negative statement, positive tag)

Ms. Zeller has a new car. Doesn’t she?

Ms. Zeller has a new car. Doesn’t she?

In tag questions, the corresponding pronoun and the first verb of the corresponding yes/no question are used. Also, notice that with positive statements, negative tag questions are used and vice versa. See also: Grammar: Yes/No Questions

Common mistakes:

You are the zookeeper. Yes (Incorrect)

You’re the zookeeper. Aren’t you? (Correct)

You come from Canada. No? (Incorrect)

You come from Canada. Don’t you? (Correct)

You’re the boss. Are you? (Incorrect-in most situations)

You’re the boss. Are you? (Incorrect)

Simon is from Singapore. Isn’t it? (Incorrect)

Simon is from Singapore. Isn’t he? (Incorrect)

Some modals can be used in tag questions: can, will, would, could, should and must.

Mr. James will be at the ceremony. Won’t he?

They couldn’t do it. Could they?

Note: When the subject is "I" and the statement is in present tense, aren’t is commonly used for tag questions.

I’m the winner. Aren’t I?(Common usage)

I’m the winner. Am I not?(Formal)