Should – weak obligation and advice

The modal verb should expresses weaker obligation than must and have to.

Should - to express obligation

Structure: should + infinitive

We use should for the present and the future.

We use should to give advice to someone and to say that something is a good idea.

Should is weaker than have to or must.

You should tell them the truth.
You shouldn't smoke, it's bad for you.
I don't think you should do it.