Modal (CAN/COULD/BE ABLE TO, MAY/MIGHT, HAVE TO/MUST/SHOULD)
Matias doesn't know what to do. He _____ decide.
can't (nie może się zdecydować)
The game tomorrow is very important for us. We ______ win!
must
It's late and you're very tired. You _______ go to bed. (advice)
should (powinieneś iść do łóżka)