should / ought to / had better 皆可用於提供建議，這三個助動詞/片語後面都接原形動詞。
例如
It’s raining. You should take your umbrella with you.
You look tired. You ought to go home and take a nap.
You’re going to be late. You had better hurry.

had better 在英語口語中常縮寫為 ’d
例如
I can’t find my credit card. I don’t know where that is. I guess I’d better call the credit card company.

had better 通常隱含可能發生之不良後果的警告
例如
You have a big test tomorrow. You’d better stay home tonight and study.

had better 的否定為 had better not
例如
You’d better not eat that meat. It looks spoiled.

 詢問意見或建議時用 should，不用 had better 及 ought to
例如
What should I wear to the party tonight?
Should I wear the red dress or the white one?

使用正確的助動詞
You will better not be late.
You’d better not be late.

should的否定應直接在should後面接not即可，不需要使用助動詞do
Mary don’t should stay up too late tonight.
Mary shouldn’t stay up too late tonight.

had better中間不加to，後面接原形動詞
He’d to better not missing any more classes.
He’d better not miss any more classes.

ought的後面需要有to才可以接原形動詞
She ought go to bed early tonight.
She ought to go to bed early tonight.

should或 should not後面接原形動詞(情態助動詞的文法)
I should not to be late for work again.
I should not be late for work again.