課本中不會(huì)教你的[O]518　ought to和should

518　ought to和should

◎ ought to和should意為“應(yīng)該，應(yīng)當(dāng)，總應(yīng)該”，為情態(tài)動(dòng)詞，沒有人稱、時(shí)態(tài)變化。

① ought to do sth.可表示責(zé)任或義務(wù)，指道義上應(yīng)該做的事。可表示現(xiàn)在、一般將來或過去將來。

We ought to pay what we own. 欠債還錢，理所應(yīng)當(dāng)。

You ought to respect the old. 你們應(yīng)該尊敬老人。

There ought not to be much noise in a hospital. 醫(yī)院里不該喧鬧。

You ought to take part in the meeting tomorrow. 你應(yīng)該參加明天的會(huì)議。

② ought to可表示“應(yīng)有的結(jié)果”或“當(dāng)然的事”。

You've been roommates for four years，so you ought to know her well. 你們同住一室已有四年了，應(yīng)該很了解她。

If he started at seven，he ought to be here now. 要是他七點(diǎn)鐘出發(fā)，這會(huì)兒該到了。

He is from Japan；he ought to know Japanese. 他是從日本來的，當(dāng)然懂日語。

③ ought to在口語中可表示“愿望”。

You ought to read the book twice. 這本書你要看兩遍才好。

We ought to see the flower show. 我們?nèi)タ纯椿ㄕ共藕谩?

④ ought to在語氣上比 must 弱，但比 should 強(qiáng)。比較：

You ought to finish the task today. 你應(yīng)該今天完成這項(xiàng)任務(wù)。

You should finish the task today. 你該今天完成這項(xiàng)任務(wù)才是。

You must finish the task today. 你必須今天完成這項(xiàng)任務(wù)。

⑤ ought to have done sth.表示“應(yīng)該做某事而未做”，含有責(zé)備、遺憾等意。

You ought to have returned the book last week. 這本書你上周就該還的。

Why did you not tell me the truth？You ought to have done so. 你為什么不告訴我實(shí)話呢？說了實(shí)話就好了。

The child ought not to have been allowed to go alone the other day. 那天，本不該讓這孩子一人去的。

⑥ ought to的否定式和疑問式。

A：Ought I to go there？我應(yīng)該去那里嗎？

B：Yes，you ought. 是的，應(yīng)該。

B：No，you ought not. 不，不應(yīng)該。

It ought to rain after this long drought，oughtn't/shouldn't it？旱了這么久，也該下雨了，不是嗎？

Oughtn't he to give them more care？難道他不該給他們更多的幫助嗎？

⑦ should指主觀上感到有責(zé)任或義務(wù)去做某事。should+完成式表示過去的動(dòng)作，常含有責(zé)備、遺憾的意味，表示“本應(yīng)該，應(yīng)該已經(jīng)”，而實(shí)際上卻沒有。

She should have shut the door against him. 她本應(yīng)該將他拒之門外的。（但沒有這樣做）