ought to和 had better


ought to+原形動詞表示義務、勸告或推測等意義，意思是"應該…"。
I am tired. I ought to sit here for a while.
我累了，我應該休息一會兒。

表示否定時,not放在ought之后。在美語中,在否定句中,ought之后的不定詞符號to?？墒÷浴?br />Hey, boy, you oughtn't (to) sleep here. Get up!
嘿，孩子，你不應該躺在這兒。起來！

在美語中,在疑問句中,ought之后的不定詞符號to常可省略。
Ought you (to) do it?
你應該這么做嗎？

had better只有一種形式,不是表示過去,而是指現在或未來,表示向對方提出勸告或警告。had better+原形不定詞表示"最好..."。
You had better give up smoking.
你最好把煙戒掉。

had better的否定形式是had better not。
You had better not throw it on the ground.
你最好別把它扔在地上。

had better很少用于疑問句,但有時為了表示忠告或建議而用否定疑問句,這時否定副詞not位于主語之后。
Had you better not talk to yourself?
你不要自言自語好不好?