Should do, should have done, ought to

Give advices, make recommandations, express your personal opinion. 

SHOULD = modal verb.
Affirmative: You should do it.
Negative form: You should not do that! (or shouldn’t ).
Interrogative form: Should I do that?

Uses:
« Should » is used to:
give an advice, make a recommendation, give your personal opinion,
express obligation as well as expectation, make hypothesis.

1/ Give an advice:
You should buy a new car.
You should see with him about it.
I don’t know, you should see a doctor, you should ask a lawyer.
You’re tired, you should go to bed early tonight.

2/ Make a recommendation:
You should respect the law.

You should buy a new house.

3/ Give your personal opinion:
Often introduced by « I think ».

I think he should do a great work.
I don’t think they should sell their products.
Do you think I should tell him?
Should we invite them? Yes, I think you should!

4/ Make hypothesis:
We should arrive at nine o’clock.

5/ Should < Have to < Must:
MUST (obligation) is stronger that SHOULD (advice):
You should do it. (it’s an advice)
You have to apologise. (strong recommandation).
You must apologise. (obligation, you have no alternative!)

6/ Should have done, Shouldn’t have done: Past tense:
We express past events that didn’t happened with « should have done ».
You should have done it: You didn’t do it, but it would have been better to do it.
I invited you, but you didn’t come! Why? You should have come. We had fun.
You shouldn’t have done it: You did it, but it would have been better to NOT do it.
Why did you come? You shouldn’t have come here.
I shouldn’t have done it: you did something and you regret it.
I shouldn’t have phoned you so late. Excuse me. Forgive me.

7/ Ought to do something = should do something
You ought to do it = you should do it.
You can use « ought to » instead of « should » in the sentence.

8/ Negative form: should not (shouldn’t): Express advices or give opinions:
You shouldn’t drive so fast.

ENGLISH SHOULD: