end of sentences. We often use them to check that person we are speaking to agrees with us or to check that we are right. If the sentence is positive, the tag is negative. E.g. She is happy, isn’t she? E.g. They are here, aren’t they?
modal verb, we repeat it in the question tag. E.g. This is a big house, isn’t it? We can go to cinema, can’t we? Note: There is always a comma before the question tag. We usually use contractions in the negative form. E.g. You’re very excited, aren’t you?