1. Often used in auxiliary functions to express an opinion, suggestion, preference, or idea. Ex : You should rest at home today.

2. Used to express that you wish something had happened but it didn’t or couldn’t (should + have + past participle). Ex : We should have visited the place on the way.

3. Used to ask for someone’s opinion. Ex : What should we do now?

4. Used to say something expected or correct. Ex : We should be there this evening.