Question: what is the difference between do you and are you?
Answer: 'Are you? ' is the interrogative form of the sentence: 'You are', where the verb 'to be' is used as a notional verb meaning 'to exist'. In ' Do you? ' the verb 'do' is an auxiiary verb used for forming the question in the simple present tense; it can be used like that in tag-questions e.g. You don't like it, do you?