They should introduce each other to their families as spouses.
You shouldn't speak so loud to your mother.
You needn't/don't have to bring any money. I'll pay everything.
You mustn't/must not cheat on Liz. She'll be upset if she finds out.
He might have lost.
Come to the party! You could meet someone interesting.
You ought to/ should have a rest before going out.
I would like to work on a new project.
He doesn't have to finish his homework.
You mustn't/ must not tell Mary about this.