We use ‘should’ for giving advice.
- You should speak to him about it.
- He should see a doctor.
- We should ask a lawyer.
We use ‘should’ to give an opinion or a recommendation.
- He should resign now.
- We should invest more in Asia.
- They should do something about this terrible train service.
‘Should’ expresses a personal opinion and is much weaker and more personal than ‘must’ or ‘have to’. It is often introduced by ‘ I think’.
- I think they should replace him.
- I don’t think they should keep the contract.
- Do you think we should tell her.