3. Choose the right variant

1. Can/could you explain me the grammar rule? (you are talking to your friend)
2. Bess might/may go to the theatre tonight. (you are 50% sure)
3. Mary must/ have to clean her room because Mary’s mother asked her to do it.
4. I want to look great. I have to/must stop eating junk food.
5. I have to/must stop drinking coffee. My doctor said it is bad for my heart.