- are followed by the base form of the verb without to.
- have the same form with all subjects (no –s or –ing).
 Should and Ought to 
Should and ought to are modal verbs (L2U2L3) that we use to give advice, a suggestion or an opinion. They both mean the same thing: that it’s a good idea to do something. For example: You’re very tired. You should go to bed.
I ought to study for my test tomorrow.
We use shouldn’t when it’s a bad idea to do something. We don’t usually use the negative form of ought to. For example: You shouldn’t eat all that pizza. It will make you sick. Like all modals, should and ought to:
Should can also be used to form questions, when asking someone for advice, or asking if something is a good idea. We don’t generally use ought to when asking questions. For example: Should I bring something to the party?
What should I bring?
To ask a wh- question, add the wh- question word before the verb. For example: Where should I run?
What should they bring to the party?
Had better Had better is the same as should and ought to, but it is usually stronger. It is sometimes used as a warning. It is followed by the base form of the verb and takes the same form with all subjects. We usually use had better in a contraction (short form). For example: I’d better finish my homework.
You’d better come inside now.
To form the negative of had better, we add not. It is used to indicate that it’s a bad idea to do something, like shouldn’t, but stronger. For example: He'd better not follow me.
They’d better not eat all the pizza.
We use had better in the present or future only. For example: You had better take your medicine now.
We’d better not be late tomorrow.
We don't use had better when we want to ask people politely to do something. We use should / ought to / could (L2U3L2) for that. That is why we don't use you had better when talking to teachers, bosses or older people. For example: When should I meet you? | |||||||||||||||||||||||||||||||||||