[Modal auxiliaries] Advisability: had better/should/ought to

You ‘d better take care of it. Had better = 'd better	Sometimes in speaking, had is dropped. 注意：沒有 have better
We should at least be wrinkle-free. Drivers should obey the speed limit.
I ought to (“otta”) study tonight, but I think I’ll watch TV instead.	Ought to is not commonly used in the negative. If it is, the to is sometimes dropped: You oughtn’t (to) leave your keys in the car.