CAN: be able to + verb She will be able to do it tomorrow. They were not able to come. Will you be able to bring it next week? MUST: have to + verb We will not have to go there. I had to buy new curtains. Did you have to go there? MAY: be allowed to + verb We are allowed to stay out until 8 p.m. Will we be allowed to go to the cinema? They were not allowed to buy anything. Note: These expressions can be also used in the present tense. I am able to win the tournament. Is he allowed to buy a dog? You have to send the letter today.