We use should and shouldn't to give advice or to talk about what we think is right or wrong.

You should means something like I think it is a good idea for you to do it.

You shouldn't means something like I think it is a bad idea for you to do it.

Should is used to express the opinion of a speaker and often follows I thinkor I don't think.


Examples     You look tired. I think you should take a few days off.

     Alice works very long hours. She should to talk to her boss.

     - I have an English test tomorrow.
     - I shouldn't worry if I were you. You have worked really hard.

     - I never have enough money.
     - I don't think you should go out so much.


Should - Quick Grammar NoteTo give advice to someone you can also say:
I should do it if I were you.I shouldn't be so rude, if I were you.When you regret not doing something in the past, you can say:
I shouldn't have spoken to him like that.I should have apologized earlier.