Wah How to use "Should"

Should is a modal auxiliary verb. It is used to express the speaker’s opinion at the moment of speaking

Affirmative           

• I should go.
• He should go.

Negative

• I shouldn't go.
• He shouldn't go.

Interrogative

• *Should I go?
• Should he go?

*Questions with Should I / we …?  are unusual.We usually say..
Do you think I / we should …?

A typical mistake in the use of should is using to before the verb.

This is never done. I should to go  is incorrect.

We use should to give advice. Don't confuse should with must.

We use must to indicate obligation. 

• You must go to school now if you don't want to be late.

We use should to give our opinion. 

• You should talk to your mother about you problems.

We can use really to add emphasis. 

• You really should spend more time with your family.

Note: Should, like Ought, is a modal verb.