高中语法专练：iv. shall, should, ought to

iv. shall, should, ought to

1. shall的基本用法：

构成将来时态，单纯表示将来的动作。

I shan't be coming back today.

我今天不会回来。

We shall read about this tomorrow.

我们明天将要读到有关这件事的文章。

2. shall在运用中需要注意的问题：

1）在疑问句中用于第一、三人称，表示向对方征求意见或提出请求。

Shall I open the door for you?

我给你开门好吗？

When shall he be able to leave the hospital?

他何时能出院呢？

2）在陈述句中多用第二、第三人称作主语，表示说话人的一种情感或意志（如表示命令、允许、决心、警告、威胁等）或者法律规章的规定。

You shall have a new i-phone on your birthday.

你的生日时将得到一款新i-phone手机。

You shall fail if you don't work harder.

你若是不更努力，就会失败。

He shall have the book when I finish reading it.

我一读完他就可以拿到这本书。

3. should的基本用法

1）should可用作shall的过去式。只适用于直接引语变间接引语，构成过去将来时。

I said I should be there before dark.

我说我将在天黑前到那里。

—I shall go for the holiday next week.

—You said you should go for a holiday the next week, right?

——我下周要去度假。

——你说你下周要去度假，对吗？

2）表示应该做，而且有一种道义上的责任。也有表示估计或推测之意。

I should help him because he is in trouble now.

我应该帮助他因为他正处于困境中。

The report was written after careful investigation, so it should be reliable.

这个报告是仔细调查后写出来的，因此它应该是可靠的。

4. should在运用中需要注意的问题：

1）在一坚持（insist），二命令（order, command），三建议（advise, suggest, propose），四要求（ask, demand, require, request）等动词后跟的宾语从句中和名词后跟的表语从句及同位语从句中，用“should +动词原形”（should经常省略）的形式。

He suggested that it (should) be done right now.

他建议立刻干这件事。

He gave the orders that the work (should) be started at once.

他发出命令这项工作应该立刻开始。

2）should可表示“万一”，用于if引导的非真实条件句中，虚拟语气表示对将来的事情的猜测。

If it should rain tomorrow, we would not go to the botanical garden.

如果明天万一下雨，我们就不会去植物园了。

3）表示惊异、赞叹、不满意等情绪，也表示比较难以相信或不应该发生的事情。

I am surprised that he should eat so little every day.

我很吃惊他每天竟然吃这么少。

You can't imagine that a well-behaved gentleman should be so rude to a lady.

你不能想像一个举止文雅的绅士竟然对一位女士这么粗野。

4）用在“It is +形容词(natural, necessary, important, essential, right, impossible, strange）+ that + ... should + do”结构中，表示理所当然、奇怪、必要、惊异等。

It was natural that he should feel hurt.

他觉得受到了伤害这很自然。

It is strange that he should be assigned to do the work.

很奇怪他竟然被分配做这项工作。

5）用于so that, lest, in case等引导的从句中。

Take an umbrella in case it should rain tonight.

带把雨伞吧以免今天夜里有雨。

6）should be doing表示推测，意为“应该正在”，而实际上没有。

You shouldn't be reading a novel. You should be reading a textbook in class.

你不应该在读小说，你应该在课堂上读课本。

7）should have done = be to have done = ought to have done = be supposed to have done，表示过去应该做某事而实际没做。

It's ten o'clock. She should have arrived in the office by now.

现在十点了，她现在本来应该到办公室了。

8）shouldn't have done表示过去不该做某事而实际上做了某事。

You shouldn't have got up so early； it is still early.

你不该起床那么早，天还黑着呢。

5. ought to的基本用法

1）表示推测、估计、可能性、（按道理）应该、应当。

You ought to start at once if you want to catch your train.

如果你想赶上火车就应该马上动身。

2）表示劝告、建议。

You ought to be reviewing your lessons now.

你现在应该在复习功课了。

6. ought to在应用中需注意的问题：

1）ought to have done = should have done，表示本该做某事而没有做。

I ought to have helped her, but I never could.

我本来应该帮助她，但是我从来没能够帮。

2）ought to be doing = should be doing，表示现在应该正在做某事。

It is 12 o'clock, he should be having lunch now.

现在是12点，他应该正在吃午饭。

3）oughtn't have done = shouldn't have done，表示本不该做某事而做了。

You oughtn't have spoken to her in that way.

你本不该对她那样说话的。

4）should = ought to，表示应该，但是should多用来谈自己的主观看法，ought to用来表示客观看法，即根据法律、义务和规定来谈论“应该或者不应该”。

The diet should be maintained unchanged for about a year.

这样的饮食应保持约一年不变。

One ought not to cross the street against the red light.

人们不该在红灯时过马路。

专项练习

1. My sister _______ here by now, for she took the early train.

A. must arrive

B. can arrive

C. may arrive

D. ought to have arrived

2. You went to the wrong shop. You ought _______ to the shop next to the cinema, but you went to the shop by the Post Office.

A. go

B. to go

C. have gone

D. to have gone

3. Tom ought not to _______ me your secret, but he meant no harm.

A. have told

B. tell

C. be telling

D. having told

4. There _______ be any difficulty about passing the road test since you have practised a lot in the

driving school.

A. mustn't

B. shan't

C. shouldn't

D. needn't

5. Mr White _______ at 8:30 for the meeting, but he didn't show up.

A. should have arrived

B. should arrive

C. should have had arrived

D. should arrive

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