Do you think you can/could/are able to win a pub quiz?
be able to
He may / might arrive in time.
Drivers in Britain must/have to/need to be at least 17 years old.
You don't have to/needn't do this task if you don't want to.
don't/doesn't have to
You should/ought to study more if you want to pass this subject.
May/could I have something to eat?
People mustn't smoke in public transport.
He brings her flowers every day. He must be in love.
He bought a Ferrari. He can't be a poor person.