Modals II

Can - Can't - Should - Shouldn't - Ought to - Had ('d) better

You can improve your grade if you study harder.

We can’t complete the lab report in just 10 minutes.

Students can choose between Music and Drama this term.

We can finish the Science project by Friday if we start now.

She can’t be in two classes at the same time.

I can’t draw realistic portraits in Art.

Can - Can't

• We use can to give permission and can't to refuse permission.
• To talk about what is possible or impossible in a situation.

Students can choose their own partner for the History project.

We can’t go on the field trip unless we return the permission form.

He should ask the teacher for help with the Math homework.

You ought to read the instructions before starting the lab.

They had better bring their materials to Art class.

You shouldn’t leave your English project until the last minute.

He ought to take better notes in Literature.

You shouldn’t cheat on a test.

Should(n't) - Ought to - Had better 

• We use should, ought to and had ('d) better in advices and recommendations.
• Commonly ought to is to formal advices.
• Had better is used to strong advices and warnings. It implies a negative consequence.
• Ought to and had better are not used in questions.