What are the question tags for sentences containing may, must, let's, and let us? Are the tags used in the following sentences correct?
may
1. I may buy a car tomorrow, mightn't I?
2. I may buy a car tomorrow, won't I?
must
3. You must be tired after that long walk, mustn’t you?
4. It must be very cold outside, isn't it?
let's / let us
5. Let's go to the movies tonight, shall we?
6. Let us go to the movies tonight, will you?