情态动词和虚拟语气

1、 考点分析

结构图

概述 can和could的用法

may和 might的用法

must的用法

need和dare的用法

情态动词 基本用法 shall和 should的用法

will和 would的用法

ought to的用法

used to的用法

had better与would rather的用法

must, can, could, may, might表推测的用法

其它用法

"情态动词+have+done" 结构的含义及用法

语气的定义和种类：

　l、语气：语气是动词的一种形式，它表示说话人对某一行为或事情的看法和态度。

　　2、语气的种类：

　　(1)陈述语气: 表示动作或状态是现实的、确定的或符合事实的，用于陈述句、疑问句和某些感叹句。如：We are not ready. 我们没准备好。What a fine day it is!多好的天气啊!

　　(2)祈使语气: 表示说话人的建议、请求、邀请、命令等。如: Open the door, please。请打开门。

(3)虚拟语气: 表示动作或状态不是客观存在的事实，而是说话人的主观愿望、假设或推测等。如: If I were you, I should study English. 如果我是你，我就学英语了。May you succeed! 祝您成功！

 

2、 专题详解

一、概述

情态动词表示说话人对某一动作或状态的态度，认为"可能、应当、必要"等等，但本身意义不完全，不能单独作谓语，必须和其他动词一起构成谓语。除ought, used, have后跟不定式外，其他情态动词一律跟动词原形。情态动词主要有：can/could, may/might, must, ought to, used to, need, dare, shall/should, will/would, have to等。

 

二、基本用法

(一) can和could的用法

1． 表示能力，可译为"能，会"。 I can swim. 我会游泳。 Emily can dance well and her mother could dance well when she was young. The cinema can seat 1,000 people.

I could not read such an easy book when I was 7 years old.

2． 表示允许、许可，常用在口语中。could比can语气上要客气。 --- Could I use your dictionary? 我可以用一下你的字典吗？ ---Yes, go ahead. 可以，用吧。（或Yes, you can. 但不能说Yes, you could.） Could/ Can you tell me how to get to the zoo? 劳驾，你能告诉我怎么去动物园吗？ He asked me whether he could take the book out of the reading room.

3. 表示可能（理论上或是逻辑判断上）。

The temperature can fall to –60℃, that is 60℃ below freezing.气温可降至—60℃，也就是零下60℃。

You mustn´t smoke while you´re walking around in the wood. You could start a fire.

在林子里走时勿吸烟，那样可能会引起火灾。

3．表示推测，可用于肯定句（can罕见）、否定句和疑问句，但更常见于疑问句或否定句。在此种用法中can和could没有时态的区别，只是表示可能性的大小，can表示推测的可能性比could大。 Can he be ill at home? 他会是生病在家吗？ Can the story be true? 这个故事会是真的吗？ He cannot be at home. 他不可能在家。 You mustn't smoke while you are walking around in the woods. You could start a fire.

4．表示惊异、怀疑、不相信等态度，主要用于否定句和疑问句中。 How can you be so careless? 你怎么这么粗心？ Where can could they have gone? 他们会去了哪里？ He can't/couldn't be over sixty. 他不可能超过60岁。

5．Could可以用在虚拟条件句中。 If I could fly, I should be very happy.

If you had followed my advice, you could have finished it.

If you had tried harder, you could have passed your exam.

６．can与be able to的区别

①can表示"能力"时，和be able to相当，许多场合都可以互相替换。但当叙述过去经过一番努力才能完成的事情或前面有特殊说明，表示你有能力时，只能用be able to。

【正】Can you speak any foreign languages? 你会说外语吗？【正】Are you able to speak any foreign languages? 你会说外语吗？【误】The fire spread the building quickly but everybody could escape. 【正】The fire spread the building quickly but everybody was able to escape. 大火迅速蔓延到整幢大楼，但大家都逃了出来。【正】The fire spread the building quickly but everybody managed to escape. 大火迅速蔓延到整幢大楼，但大家都想法逃了出来。

②be able to 比can有更多形式。 No one could answer the question.没人能回答这个问题。(这里could可用was able to 代替） When he grows up, he will be able to support his family. 他长大后就能养家了。 Frank is ill. He hasn't been able to go to school for one week. I'm sorry for not being able to help you in time. 对不起，不能及时帮你的忙。

③could经常和动词see, hear, smell, taste, feel, remember, understand等连用。 When we went into the house, we could smell something burning. 当我们走进屋子时，我们闻到什么东西烧焦了。（不用was able to） She spoke in a very low voice, but I could understand what she said. 虽然她讲话的声音很低，但我还是明白了她说的话。

④在谈论说话时发生的动作，用can，不用be able to。 【误】Look! I'm able to swim. 【正】Look! I can swim. 看，我会游泳了！

 

(二) may和 might的用法

1．表示请求、许可，常译为"可以"。

在口语中可用can, could代替may，但在正式场合用may。表示允许时，也可用might代替，might不表示过去时，而是表示口气比较婉转。

You may take this seat if you like. 如果你喜欢可以坐这个位置。

May/Can /Could/ Might I have a talk with you ? 我可以和你谈谈吗？

--- May/Might I come into the room to see my mother? 我可以进房间看我母亲吗？

--- No, you mustn't. She needs to have a good rest. 不，你不能进。她需要好好休息。

提示：

May I ... 问句常见的肯定回答和否定回答。

肯定回答Yes, please. Certainly. Yes, of course. Sure. Go ahead, please.

否定回答 No, you can't. （最常见）No, you mustn't. （具有强烈禁止的意思）

Please don't. You'd better not. I don't think you can. I'm sorry it's not allowed.

2．表示推测，可译为"可能，也许"。

Your math teacher may/might be in his office. （一般情况下，might表示的可能性很小）

The light isn't on. It may/might be broken. 那盏灯没有亮，它可能坏了。

There may/ might be some ink left in the bottle. 瓶子里也许还剩点儿墨水。

注意：

用may表示推测一般不用于疑问句，在疑问句中通常用can来代替。

Can he be at home? 他可能在家吗？

--- Can it be true? 这可能是真的吗？

--- It may be, or may not be. 可能是，也可能不是。

3．用在目的状语从句中，构成谓语。

He wants to take a taxi so that he may get there in time.

他想坐出租车，这样他就能及时到达那里。

I arrived at the airport earlier in order that I might meet him.

我早早地就到了机场为了能接到他。

4． 有时可以用于祈使句表示祝愿。

May you succeed. 祝你成功 May you be happy. 祝你快乐。

May that day come soon. 希望这一天早日到来。

 

(三) must和have to的用法：

1．must表示有做某一动作的必要或义务，强调主观看法，可译为"必须，应该"。 Everyone must obey the rule. 人人都必须遵守制度。 We must do everything step by step. 我们必须逐步做每件事。 Teachers must be patient enough with their students. 老师必须对学生有足够的耐心。

2．have to 表示因客观需要促使主语不得不做某事。 You can't turn right here. You have to turn left. 你不能在这里右拐，你必须左拐。 My eyesight is very poor. I have to wear glasses for reading. 我的视力很差，看书时不得不戴眼镜。 You have to pass a test before you can get a driving licence. 你在取得驾照之前必须先通过考试。 提示： 在口语中，我们可以使用have got to来代替have to. I've got to work on Sunday. 我不得不星期天工作。 When has Ann got to go?安必须什么时候走？

3．must 与have to的比较。 must 与have to在表示"必须"这个意思时意义相近，但在用法上有所区别。 ①must含有说话者的强烈决意（表示主观的看法），have to 则表示外力环境或习惯使然（即表示客观的必要，作"不得不"解）。 I must study hard. 我必须努力学习。（发自内心的决定） I have to study hard. 我不得不努力学习。（外界因素逼迫） You must stay for supper. 你必须留下来吃晚饭。（because I want you to） You have to stay for supper. 你得留下来吃晚饭。（because there is nowhere else to go） ②must只有一种形式，而have to可有多种时态。 They had to put off the sports meet due to the bad weather. 由于坏天气，他们不得不推迟运动会。 These last two days he has had to take a rest at home. 这两天他必须一直在家休息。 ③must的否定式和have to的否定式的意思完全不同。 You must keep it a secret. You mustn't tell anyone. 你必须保密，你不可以告诉任何人。（mustn't表示"禁止"） You don't have to tell me the secret. 你不必告诉我这个秘密。（don't have to意思是"没有必要"= don't need to）

4．must用于表示推测，它的肯定程度比may, might, could大得多，一般只用于肯定句。 ①must do (这里的do通常是状态动词或系动词) ，表示对现在状态的推测。 He must be very lazy for his desk is very untidy. 他肯定很懒，因为他的课桌很不整洁。 Carol must get very bored with her job. She does the same thing every day. 卡罗尔肯定对她的工作厌烦了，她每天都做同样的事。 ②must be doing表示对现在动作或状态的推测。 Put on more clothes. You must be feeling cold with only a shirt on. 多穿点儿衣服，你只穿一件衬衣，肯定觉得冷。 ③must have done表示对过去的动作或状态的推测。 The ground is wet. It must have rained last night. 地面是湿的，昨晚肯定下雨了。 I didn't hear the phone. I must have been asleep. 我没听见电话铃响，我一定是睡着了。 提示： must表示推测只用于肯定句，否定句和疑问句要用can, could来代替must。 He's just had his lunch. He can't be hungry already. 他刚吃过午饭，不会饿的。 They have just arrived here. They can't know many people. 他们刚到这里，不可能认识很多人。 Leslie walked past me without speaking. He can'tcouldn't have seen me. 莱斯利从我身边走过而没打招呼，他肯定没看见我。

5．must可用来表示根据逻辑推理必然要发生的事，可译为"必然会，总是会"。 We all must die. 我们都会死。 Truth must be out. 真相必然会大白的。 Winter must be followed by spring. 冬天到了，春天还会远吗？

6．must有时可用来表示"偏偏"的意思。 Why must it rain today? 为什么偏偏在今天下雨？ When I was taking a nap, a student must knock at the door. 正当我午睡时，偏偏一个学生在这个时候来敲门。

 

(四) need和dare的用法

1．作情态动词：

need表示"需要"或"必须"，仅用于否定句或疑问句中，在肯定句中一般用 must，have to，ought to，或 should代替（注意其一般疑问句的回答方式与must完全一样）；dare主要用于疑问句、否定句和条件状语从句中，一般不用于肯定句。例如：

You needn't come so early.

Need I finish her work today? ---Yes，you must./No，you needn't.=No，you don't have to.

Dare he do it？---No，he daren't.

How dare you say I'm unfair．

If you dare come here，I will come to meet you.

He daren't speak English before such a crowd，dare he?---Yes，he dare./No，he daren't.

注意：needn't have done"表示本来不必做某事而实际上却做了某事"。例如：

You needn't have waited for me．

2. 作实义动词：

dare和 need后面接不定式（to do），有人称、数和时态的变化，变否定句和疑问句时要借助于助动词。所不同的是，作实义动词时，在肯定句中，dare后面通常接带 to的不定式；而在否定和疑问句中，dare后面的不定式可以不带to．例如：

I dare to swim across this river.

He does not dare (to) answer.

I wondered he dare (to) say that．

Does he dare to go there？---Yes，he does./No，he doesn't.

He needs to finish it this evening．

He doesn't need to finish it this evening.

Does he need to finish it this evening？---Yes，he does./No，he doesn't.

 

(五) shall和 should的用法

1．shall ①表示征询意见或请求指示，用于一、三人称疑问句。 Shall I carry it for you? 我来帮你搬它，好吗？ Shall we sing a song? 我们唱一支歌，好吗？ Shall they wait outside? 让他们在外面等吗？ Shall the waiter bring meals to your room? 要服务员把饭送到你房间去吗？提示： Shall I open the window? 我打开窗子好吗？ Will you open the window? 你打开窗子好吗？ Shall he open the window? 他打开窗子好吗？ ②表示说话人的意愿，有"命令、允诺、警告、决心"等意思，用于第二、三人称陈述句中。 You shall do as I say. 按我说的做。（命令） He shall be sorry for it one day, I tell you. 我告诉你，总有一天他会后悔的。（警告） You shall fall behind in your exam if you keep playing..如果你一直玩，你就会在考试中落后。 Nothing shall stop us from carrying out the plan.什么也阻止不了我们执行这项计划。（决心） He shall have the book when I finish reading. 我看完这本书就给他看。（允诺） I shall do my homework after reading this story book.. 读完这本故事书后我就做作业。

③表示强制，用于法令、条约、规章中，意为"必须，应该"。如：

Candidates shall remain in their seats until all the papers have been collected. 试卷完全收回后，应试人才能离开座位。

2．should

①表示义务，意为"应该"（某件事宜于做），用于各种人称。

Children should obey their parents. 儿童应该服从他们的父母。

One shouldn't be selfish. 人千万别自私。

Customers who get bad service should complain, shouldn't they

没有得到满意服务的顾客应该抱怨，不是吗？

②常与what, how, why等词连用，表示意外、惊讶等情绪。

How should I know? 我怎么会知道呢

Why should I fear? 我为什么会害怕？

What should she do but cry for help? 除了呼救外，她还能干什么？

I don't know why you should think I did it. 我真不知道你凭什么认为这件事是我干的。

③表示对过去、现在或将来情况的某种推测，可译为"可能、照说应该"。

It should be fine tomorrow. 明天可能天是晴天。

He should be taking a bath now. 他可能在洗澡。

It's nearly seven o'clock. Jack should be here at any moment.

已经快七点了，杰克随时都可能到这儿。

The film should be very good as it is starring first-class actors.

这部新电影是一流演员主演的，估计拍得很好。

④表示对现在或以前的动作的责怪、批评（应做的事却没做）。

The boys shouldn't be playing football. They should be at school.

这些男孩子不应该在踢足球，他们应该在上课。

You shouldn't have entered the teachers' office without permission.

没有允许你们不应该进老师办公室。

 

(六) ought to的用法

1．表示义务，意为"应该"（因责任、义务而该做），口气比should稍重。 We ought to defend our country. 我们应当保卫我们的国家。（每一个公民应尽的义务） You ought to respect your parents. 你应当尊敬你的父母。 Oughtn't we to do everything possible to stop pollution. 2．表示推测，暗含很大的可能，可译为"应该是，会是"。 Prices ought to come down soon. 价格可能会很快下跌。 Han Mei ought to know his telephone number. 韩梅该知道他的电话号码。 There's a fine sunset; it ought to be a fine day tomorrow. 今天有晚霞，明天应该是个好天。 3．ought to和should一样，表示对现在或以前应做的事却没做的责怪、批评。 You ought to be washing your clothes. Why are you playing Ping-Pong 你应该在洗衣服（可是你没洗）。为什么你在打乒乓球？ You ought to have handed in the exercise last week. 你上周就应当交练习。（可你没交，含责备的意思。） He ought to have asked me before he took my bike. 他在用我自行车之前应该和我讲一声。

4．ought to 与should的比较。 ought to 和should的含义较近，但不完全相同。ought to表示"应该"， 是从"义务"或"按理推断"的角度来讲的。should则是从说话人的个人看法这一角度来讲的。 You are her mother. You ought to look after her. 你是她的母亲，你应当照管她。（是道义上的责任，不能和should互换。） We should encourage him for we are his classmates. 我们应该鼓励他，我们是他的同班同学啊！ 提示： 表示"义务"时，我们在口语中可以用had better或be supposed to 来代替should和ought to。 If you are not well, you had better ask Alice to go instead. 如果你不舒服，你最好叫艾丽丝代替你去。 I'm supposed to be there at 8 o'clock. 我应该八点到那里。

 

(七) will和 would的用法

1.will

1）表意愿，用于各种人称陈述句。

I will do anything for you. 我愿为你做任何事。

None is so blind as those who won´t see. 不愿看的人眼最瞎。

If you will read the book, I´ll lend it to you. 如果你愿意读这本书，我会把它借给你。

2）表请求，用于疑问句。

Will you close the window? It´s a bit cold. 请你把窗户关上好吗？有点冷。

Won´t you drink some more coffee? 再来一点咖啡好吗？

3）表示某种倾向或习惯性动作。

Fish will die out of water. 鱼离开水就不能活。 The door won´t open. 这门打不开。

The boy will sit there hour after hour looking at the traffic go by.

那男孩常常坐在那里好几个钟点，看着车辆行人通过。

2.would

would是will的过去式。注意其两种固定问句的回答方式。

Would you like…？----Yes，please./No，thanks.

Would you like to do…？----Yes，I'd love to./I'd love to，but…./I'm sorry I can't.

1）表意愿。

They would not let him in because he was poorly dressed. 他们不让他进去因为他衣着旧。

I said I would do anything for you. 我说过我愿意为你做任何事。

2）表委婉地提出请求、建议或看法。

Would you like another glass of beer? 再来杯啤酒好吗？

Would you mind cleaning the window? 请把窗户擦一下好吗？

They wouldn´t have anything against it. 他们不会有什么反对意见。

3）表过去反复发生的动作或过去的一种倾向。

Every time she was in trouble, she would go to him for help.

她每遇到麻烦都会向她求助。他告诉我盒子打不开了。

 

(八) used to的用法

1．used to表示过去的习惯或过去某时期的状况，但现在已不存在。 He used to drink tea but now he drinks coffee. 他过去总是喝茶但现在他喝咖啡了。（强调现在不喝茶了） I know where there used to be a river here. 我知道这儿以前哪里有条河。（现在没有河了） When I was a child I didn't use to like tomatoes. 我小时候不喜欢吃西红柿。 He is not what he used to be.. 他已不是原来的他了。 Where did you use to live before you came here 来此之前你住在什么地方？

疑问句

Did you use to go to the same school as your brother?

Used you to go to the same school as your brother?

否定句

I usedn't to go there.

I didn't use to go there．

2．would 和used to的用法区别。 ①used to表示过去与现在或过去某时与后来的情况有不同，强调"现已无此习惯了"，而would只表示过去的情况，与现在无关。 When he was young, he would smoke a lot. 他年轻时总是吸许多烟。（不含有和现在比较，现在他也许还在抽，也许不抽了。） He used to live in the country, but now he lives in the city. 他过去住在乡下，现在住在城里。 ②used to可表示过去的习惯动作或状态，而would只表示过去的习惯动作。 Kate used to be very thin. 以前凯特非常瘦。 There used to be a building at the street corner, but it has been pulled down. 街道拐角处过去有座楼房，现在拆了。（不用would） ③used to可泛指过去的习惯动作或状态，而would表示过去的习惯动作时，往往要带有一个特定的时间状语。 【误】We would play hide-and-seek in the fields. 【正】We used to play hide-and-seek in the fields. 我们过去常在田野里玩捉迷藏。 【正】Whenever we were in the country, we would play hide-and-seek in the fields. 每当我们在乡下，我们都在田野里玩捉迷藏。

 

(九) had better与would rather的用法

1.had better 意为"最好"，后接不带 to的不定式。例如:

-We had better go now.

-Yes，we had ( we'd better／we better had?)

Hadn't we better stop now? (Had we better not stop now?)

I think I'd better be going.(用于进行时态，表"最好立即")

You had better have done that.(用于完成时态，表未完成动作)

注：① had best与 had better同意，但较少用。

② You had better …用于同辈或小辈，对长辈不可用．

2.would rather意为"宁愿"，表选择，后接不带 to的不定式。例如：

I'd rather not say anything．Would you rather work on a farm?

-Wouldn't you rather stay here? - No，I would not，I'd rather go there．

由于 would rather表选择, 因而后面可接 than. 例如:

I would rather work on a farm than in a factory．

I would rather watch TV than go to see the film．

I would rather lose a dozen cherry trees than that you should tell me one lie．

I'd rather you didn't talk about this to anyone．(句中的'd rather不是情态动词，would在此是表愿望的实义动词)。

 

三、其他用法:情态动词+have done

1、should have done/ should not have done

它们分别表示"过去本来应该（已经）…（而实际上并没有…）"/"过去本不应该（已经）…而实际上却已经…"如：

We should have studied last night, but we went to the concert instead . 我们昨晚本应学习的，但我们却去看音乐会了。（实际上没有学习）

If he had joined us , we should have had a more enjoyable time . 如果他加入我们的活动，我们就可以玩得更开心了。（实际上没那么开心，由于他没加入我们的活动）

I should have thought of that .这一点我应该想到的。（但实际上没想到）

They shouldn't have left so soon . 他们不应当走得那么早。（但实际上还是走了）

He shouldn't have said such a thing .他当时不应该说那种话。（但已经说了）

在表示推测时，它表示的是"大概已经，或许已经"的意思。如：

The train should have already left.火车大概已经开走了。

Time is up , you should have finished your exercises . 时间已到，你们可能已经做完作业了。

2、would have done

它表示的是与过去事实相反之假设的结果，意思是"当时就会…了"，而实际上没有……。如：

I would have helped you if I had known of your difficulties . 要是我当时知道你们的窘境，我就会帮助你了（而实际上没有帮助你）

If it hadn't rained yesterday, we would have gone on excursion .假如昨天没下雨，我们就去远足了。（实际上没有去）。

在表示推测时，它表示"过去大概是……，似乎、可能……"如：

I suppose the writer would have been about thirty when he published his first work . 我想这位作家出版第一部作品时，大概是30岁左右。

3.must have done

它表示"过去一定……了"，且结果延续到现在，用于对过去发生的事进行推测。如：

No one answers the phone call, they must have already gene out ,没人接电话，他们一定已经出去了。

They must have arrived by now.现在他们想必已经到达。

You must have known what he wanted .你当时一定知道他要什么。

Where is my pen? I must have lost it . 我的钢笔在哪？我肯定把它弄去了。

4.cannot have done/couldn't have done

这两个形式表示"过去应该不可能做…"如，

He can not have promised it . 他应该不会答应那种事。

John is very clever . He cannot have told his son to do that . 约翰是很聪明的，他应该不会叫他儿子那样做。

He couldn't have said such a thing . 他应该不会说出这样的事。

5.can't have done

它表示"过去不可能做…"。如：

She can't have gone to school , we have no school today.她不可能到学校去，今天我们学校放假。

He can't have finished the work so soon .这项工作他不可能完成得这样快。

Jack doesn't work hard at all. He can't have passed this English examination . 杰克学习根本不用功。他不可能通过这次英语考试。

6.can (could)…have done

这种形式只用于疑问句，表示"含疑问语气的推测"。如：

Where can (could) they have gone?他们能到哪里去了呢？

How could he have forgotten such an important thing?这么重要的事他怎么能忘了呢？

He told me he had a meeting to attend in Beijing. Can he have gone to Beijing to attend the meeting?他告诉我说北京有个会议要参加，他会不会已位去了北京呢？

Can you have left the watch at home?你会不会把表丢在家里呢？

7.could have done

它表示"过去本来能够…" 实际上没能做…。如：

I could have run 100 meters in 12 seconds.我本来能用12秒钟完100米的。（实际上设能）

If you could have finished the task in time，you could have been promoted. 如果你当时能如期完成那任务的话，你可能已提升了（实际上没有被提升）

I could have laughed to hear him talk like that.听他那样讲话，我差点笑出声来。

In those circumstances we could have held out longer.在那样情况下，我们本来可以坚持更久的。（实际上没有坚持很久）

8.may (not) have done

它表示"对过去可能会(不会)发生的事" 的猜测。如：

She may have missed the train.她也许误了车。

He may not have achieved all his aims But his effort is a good one.他可能没达到他的全部目的，但他还是认真做了努力的。

She may have gone to the clinic.她或许到医务宝去了。

"What has happened to Tom?""I don't know,. he may have got lost.""汤姆怎么了？""我不知道，他可能迷路了。

9.might have done

a、它表示对过去发生的事一种不太肯定的猜测。如：

I thought my uncle might have missed the train..我想我叔叔可能误火车。

I might have lost my watch in the bath room.我可能把表遗忘在卫生间了。

b、它的虚拟式表示与过去事实相反的假设结果。如

If she had started a little earlier， she might have been in time for the train.如果她早点出发，她有可能及时赶上火车。(实际上没有早出发，便没有赶上火车)

It might have been better to stop them.如果那时就停上的话，也许比较好。

You might have told the truth.你本应该讲实话(实际上没有讲真话，此处有批评之意)

You might have made greater progress. 你的进步是可以更大一些的（此处含责备口气）

10.need not have done

它表示过去已做的事，事实上没有必要。如：

I need not have got up so early . 我本来不必要那么早起床的（事实上早已起床）

I need not have waited for the train for an hour. 我本来不必要等一个小时的火车。（事实上已经等了一个小时）

 

情态动词表推测的反意疑问句

1. 情态动词表推测的反意疑问句，简单来说，就是以情态动词后的时态为淮，如句子里有明确的时间状语，则以其为准。

2. 以 must 为例：

E.g. 1. You must be hungry now, aren't you?

2. He must be watching TV , isn't he ?

3 Tom must have lived her for a long time, hasn't he ?

4. She must have arrived yesterday, didn't she?

注：如选择题中（以She must have arrived yesterday, didn't she？为例）既有didn't she又有hasn't she则以didn't she？为最佳答案。

 

总结：

肯定：may/might/must do 推测的动作与谓语动作同时发生

 

情态动词 否定：can't/couldn't be doing 同时发生

表推测

疑问：can/could have done 先发生（对过去的推测）

 

have been doing 先发生一直延续到现在

should/ought to

 

情态动词 shouldn't/oughtn't to

表虚拟 have done 本该做某事 而没做

need/needn't 本不该做某事而做了…

 

could/might

 

虚拟语气

一、语气的定义和种类

　　l、语气：语气是动词的一种形式，它表示说话人对某一行为或事情的看法和态度。

　　2、语气的种类：

　　(1)陈述语气: 表示动作或状态是现实的、确定的或符合事实的，用于陈述句、疑问句和某些感叹句。如：We are not ready. 我们没准备好。What a fine day it is!多好的天气啊!

　　(2)祈使语气: 表示说话人的建议、请求、邀请、命令等。如: Open the door, please。请打开门。

　　(3)虚拟语气: 表示动作或状态不是客观存在的事实，而是说话人的主观愿望、假设或推测等。如: If I were you, I should study English. 如果我是你，我就学英语了。May you succeed! 祝您成功！

 

二、虚拟语气在条件从句中的用法

　　条件句有两类，一类是真实条件句，一类是虚拟条件句。如果假设的情况是有可能发生的，就是真实条件何。在这种真实条件句中的谓语用陈述语气。如: If it doesn't rain tomorrow, we will go to the park. 如果明天不下雨，我们就去公园。

　　如果假设的情况是过去或现在都不存在的，或将来不大可能发生的，则是虚拟条件句。如: If he had seen you yesterday, he would have asked you about it. 如果他昨天见到你，他会问你这件事的。(事实上他昨天没见到你，因此也未能问你这件事。)

在含有虚拟条件句的复合句中，主句和从句的谓语都要用虚拟语气。

 

1. 表示与现在事实相反或不可能发生：条件状语从句：一般过去时（虚拟语气中be→were）主句用：would(should, could, might)+动词原形。

If we had time now, we would read it again.

If I were you, I would work hard.

 

2. 表示与过去事实相反或不可能发生：条件状语从句：had+过去分词；主句：would(should, could, might)+have+过去分词。

If he had taken my advice, he would have succeeded in the test.

If I had known your telephone number then, I would have called you.

 

3. 表示与将来的事实可能相反或不可能发生：条件状语从句：①一般过去时②should +动词原形③were to+动词原形；主句：would(should, could, might)+动词原形。

If it should rain, the crops would be saved.

If it were to snow tomorrow, they would not go out.

 

同步练习：

1. If she had worked harder，she ____D______.

A. would succeed B. had succeeded

C. should succeed D. would have succeeded

2. If my lawyer ____A____ here last Saturday，he _________me from going.

A. had been; would have prevented B. had been; would prevent

C. were; would D. were; would have prevented

3. If he were here，he _____B_____ us how to do it.

A. told B. would tell C. had told D. have told

4. If it ____A_____ rain next week, the farmers could still have a good harvest.

A. should B. could C. would D. might

DABA

 

虚拟条件句的特殊情况

(1). 省略if的虚拟语气

如果从句中含有were/ should/ had时，则可以把这三个词置于句首，省略if.采用倒装语序。

If it should happen, what would you do? →Should it happen, what would you do?

If he had recognized me, he would have come over. →Had he recognized me, he would have come over

(2).含蓄虚拟条件句

有时候假设的情况不以if引导的条件从句形式表现出来，而是通过一个介词短语，连词或其他形式表示。含蓄条件句大体有三种情况。

　　1) 条件暗含在短语中。

　　如： But for your help we couldn't have succeeded in the experiment.

　　如果没有你的帮助，我们的实验是不会成功的。(暗含在分词短词but for your help)

What would I have done without you? 如没有你，我会怎么办呢？(条件暗含在介词短语without you 中)

　　It would be easier to do it this way. 这样做会比较容易。

　　(条件暗含在不定式短语 to do it this way中)

　　This same thing, happening in wartime, amount to disaster.

　　同样的事，如发生在战时，就会酿成大祸。(条件暗含在分词短语happening in wartime 中)

　　He must have the strength of a hippopotamus, or he never could have vanquished that great beast. 他一定是力大如河马，否则他绝不会击败那只庞大的野兽。(暗含条件是连词or)

　Alone, he would have been terrified. 如是单独一人，他是会感到害怕的。(暗含条件是alone)

　　2) 条件暗含在上下文中。

　　如： You might stay here forever. 你可以永远待在这儿。(可能暗含if you wanted to)

　　We would have succeeded. 我们本来是会成功的。(可能暗含if we had kept trying)

　　Your reputation would be ruined. 你的名誉会败坏的。(可能暗含 if you should accept it)

　　3) 在不少情况下，虚拟式已变成习惯说法，很难找出其暗含的条件。

　　如： You wouldn't know. 你不会知道。

　　I would like to come. 我愿意来。

(3) 混合/错综型虚拟语气

当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，称为'错综条件句'，动词的形式要根据它所表示的时间作出相应的调整。

If you had followed my advice, you would be better now.(从句说的是过去，主句是现在)

If I were you, I would have taken his advice.(从句是现在，主句是过去)

 

同步练习：

1__________ your address，I would have written to you.

A. Did I know B. Were I to know

C. Had I known D. If I should know

2. Yesterday, Jane walked away from the discussion. Otherwise, she ________ something she would regret later.

A. had said B. said C. might say D. might have said

3.If we __________ 200 years old，we __________ everything.

A. were to be，could change B. had been，changed

C. were，would have changed D. should be，changed

4. He ________ the job well, but he __________ so careless.

A. hadn't done, had been B. could have done, was

C. could do, was D. had done, had been

5. If I ________ with her last summer, I ________ with her now.

A. worked…am getting on very well B. had worked…would get on very well

C. had worked… would have got on very well D. had worked…will get on very well

CDABB

三、 虚拟语气用在名词性从句中

1.主语从句中的虚拟语气

这种虚拟语气主要用在it is+形容词（名词，过去分词）+that+主语+should+动词原形（should可以省略）这种结构中。

1 常见的这类形容词有：advisable, anxious, better, desirable, surprising, natural, necessary, strange, important, regretful.

2 常见的这类过去分词有：decided, demanded, recommended, requested, desired, required, ordered, suggested.

3 常见的这类名词有：duty, pity, no surprise, no wonder, regret, shame.

It was suggested that he（should）join the club activities.

It is strange (surprising, disappointing) that she (should) not have been invited.

It is a pity that he (should) refuse to accept the offer.

 

同步练习:

1. It is strange that he __________ so.

A. thinks B. think C. thought D. will think

2. It is important that I _____ with Mr. Williams immediately.

　　A. speak　　　 B. spoke C. will speak　　　 D. to speak

3. It's a pity that he ______ such a good chance.

　　A．should miss B．should have missed C．has missed D．all the above

BAA

2. 宾语从句中的虚拟语气

1） wish 后所跟宾语从句谓语动词用虚拟语气（意为要是，但愿…就好了），其形式主要有三种：

表示对现在情况的虚拟：wish后接一般过去时的从句

表示对过去情况的虚拟：wish后接过去完成时/should，could have done

表示对将来情况的虚拟：wish后接would，could+动词原形

I wish it were spring all year round.

I wish it would be fine tomorrow.

She wished she had stayed at home.

I wish you __________ him my telephone number，but you did.

A. didn't give B. hadn't given

C. wouldn't give D. shouldn't give

B

2). would rather, would sooner等表示愿望，其宾语从句常用虚拟过去式。

　　☆ 表示与现在和将来含义事实相反的虚拟语气要用动词的过去式

　　☆ 用过去完成式(had + 过去分词)表示过去事实相反的含义

　　I would rather you came tomorrow.我宁愿你明天来。

　　I'd sooner she left the heavy end of the work to some one else.我宁愿她把重活留给别人。

 

3）在表示建议，命令，要求等动词后的从句要用(should)+动词原形。此类动词有：一坚持：insist（坚持要求）；二命令：order, command；三建议：suggest, advise, propose；四要求： demand, require, ask, request.

The teacher ordered that all the books (should) be handed in on time.

 

同步练习：

1．The job would require that ______ at 7 o'clock every morning．

　 A．he will be at the factory　　 B．he be at the factory

　 C．he was at the factory　　 　　D．he has been at the factory

2. His doctor suggested that he _____ a short trip abroad.

　 A. will take　　　B. would take C. take　　　D. took

3. I wish you __________ him my telephone number，but you did.

A. didn't give B. hadn't given C. wouldn't give D. shouldn't give

4.Frankly, I'd rather you ______ anything about it for the time being.

A. do B. don't do C. didn't do D. will not do

BCBC

 

P.S. 当suggest表示'暗示，说明'之意；insist表示'坚持认为，坚持说'之意时，从句不用虚拟，用正常的陈述语气。

They insisted that he （should）be present at the ceremony.他们坚决要求他出席这次典礼。

The man insisted that he had never stolen the money.

She suggested that we (should) leave early.

The smile on his face suggested that he was satisfied with life.

 

同步练习：

1.Jane's pale face suggested that she ______ ill and her parents suggested that she ______ a medical

examination.

A. be; should have B. was; have C. should be; had D. was; has

2.The man in prison insisted that he _________nothing wrong and _________set free.

A. had done, should be B. should do, should be

C. had done, had been D. should do, had been

 

BA

 

【分析】

此题容易误选B，想当然地认为insist后的从句谓语要用"should+动词原形"这样的虚拟语气。事实上，insist后的从句谓语是否用"should+动词原形"这样的虚拟语气，要看该谓语动词所表示的含义。一般说来，若该谓语动词所表示的动作尚未发生，或尚未成为事实，则用虚拟语气；若该谓语动词所表示的动作已经发生，或已经成为事实，则要用陈述语气。对上题而言，坐牢的这个人坚持了两点：一是没做错事，二是应该释放。很显然，在坐牢这个人看来，"没做错事"应该是事实，故用陈述语气；

"被释放"还不是事实（因为他还在坐牢），故用虚拟语气。所以此题的最佳答案应为A。又如：

He insisted that I had read his letter.

他坚持说我看过他的信。（"看信"已成为事实，故用陈述语气）

He insisted that I should read his letter.

他坚持要我看他的信。（"看信"尚未成为事实，故用虚拟语气）

请再做下面一题

The patient insisted that he _________ ill and _________ to the hospital.

A. wasn't, wasn't sent B. wasn't, shouldn't be sent

C. shouldn't be, wasn't sent D. shouldn't be, shouldn't be sent

答案选B，因为在说话者看来，"没病"是事实，故用陈述语气；"不送医院"尚未成为现实，故用虚拟语气。

 

3. 表语从句和同位语从句中的虚拟语气

在表示建议，命令，要求的名词后的表语从句或同位语从句中的谓语动词要用（should）+动词原形。常见名词有：advice, desire, request, demand, proposal, suggestion, requirement, order.

He gave orders that the guests (should) be hospital entertained.

His proposal is that we (should) get rid of the bad habits.

 

My suggestion was that the meeting ______ off till next week．

　A．to put　　　　B．be put C．should put　　　D．be putting

B

四、虚拟语气在定语从句中

在It is (high/about) time that …句型中也用虚拟语气，从句常用过去式，有时也用should +动词原形，should不可省略，表示早该做而没做的事，含建议的意味。

It is time that we went home.

I think it's high time that she made up her mind.我想她该拿定主意了。

P.S.此句型中，注意与It/This is the +序数词+time that+现在完成式的区别。

This is the first time that I have been here.

 

It's high time you ______.

A. start to work B. would start to work C. started to work D. had started to work

C

五、虚拟语气在状语从句中

①方式状语从句

由as if 或as though引导的状语从句可以用陈述语气表示可能符合事实的情况，也可以用虚拟语气表示与事实不符或与事实相反的情况。

a. 表示与现在事实不相符，用一般过去时

The teacher treats the pupil as if he were her own child. （这位学生并不是她的亲生孩子）

b. 表示与过去事实不相符，用过去完成时

I felt as though we had known each other for years. （其实并没有认识多年）

c. 表示与将来事实不相符，用would/might/could

It looks as if it might rain. 天看上去好像要下雨。（不大可能下雨）

对比：

He looks as if he is young. 看样子他好像很年轻。（他就是年轻）

He looks as if he were young. 看样子他好像很年轻。（实际上他不年轻）

 

②目的状语从句

a. 由in case, lest, for fear that引导的目的状语从句，动词用"should + 动词原形"结构，表示忧虑或目的。

Please remind me of it again tomorrow in case I (should) forget.

She emphasized it again and again, lest he (should) forget.

We talked the matter over face to face for fear that there should be any misunderstanding.

b. 在in order that和so that引导的目的状语从句中，往往用can(could)或may(might)。

I shall write down your telephone number so that I may not forget.

They worked harder than usual in order that they could finish the work ahead of time.

We will tell you the truth so that you can judge for yourself.

 

③让步状语从句

让步状语从句指事实时，从句谓语动词用陈述语气。若从句内容表示现在和将来的假设情况，从句谓语动词用虚拟语气。

Though he (should) fail, there would still be hope.

I should say the same thing even if he were here.

Whether he (should) succeed or fail, we shall have to do our part.

However hard it might rain rains, we shall go there together.

No matter what his social position (might) be, a man is equal in the eye of the law.

同步练习：

1.The two students talked as if they _____ friends for years.

　A. should be　　　B. would be C. have been　　　D. had been

2. He's working hard for fear that he _____.

　　A. should fall behind　　　　B. fell behind

　　C. may fall behind　　　　　 D. would fallen behind

3. The driver looked over the engine carefully lest it ______ on the way.

A. goes wrong B. go wrong C. went wrong D. would go wrong

DAB

六、虚拟语气在其他情况中

1. if only(但愿,要是…就好了)后接从句也用虚拟语气，其形式与wish的用法一致。

If only后常接过去完成时,表示过去没有实现的愿望。

如:1) If only you had worked with greater care! (but you didn't work with greater care)

2) If only we had arrived in time, we would not have missed the train! (but we didn't arrive in time)

If only后常用过去将来时表示将来不大可能实现的愿望。

如:If only she would win!但愿她能赢!

与此句型容易混淆的还有一种结构"only if...",only置于if前表示强调if条件,意为"只要„„",用于引导陈述语气的真实条件句。

 

Only if you study hard, you will pass the test. 只要你努力学习,就会通过考试。

 

2. 动词hope, intend, mean, plan, want, think等词用过去完成的形式，表示的意思为'本想，本打算，本认为'

He had meant to buy the furniture last week, but it rained.（他上周本打算去买那件家具，但却下雨了）

I had thought he had been dead for at least 20 years.

I had hoped that she would go to the USA and study there, but she said she liked to stay in China.

 

3. 表示愿望的感叹句

在表示祝愿的感叹句中，用动词原形，表示愿望。

Long live the People's Republic of China! 中华人民共和国万岁！

May you be happy! 祝您快乐！

God bless you! 上帝保佑你！

Success attend you! 祝你成功！

The Lord save us! 愿主救我们！

 

同步练习：

1. I ___________ to stay there for one more week, but I changed my mind.

A. would have hoped B. was hoping C. had hoped D. hoped

2. If only you _____B_____ him what I said! Everything would have been all right.

A) didn't told B) hadn't told C) would not tell D) would have not told

 

课堂练习

1. He ______ you more help, even though he was very busy.

A. might have given B. might give C. may have given D. may give

2. Jenny______ have kept her word. I wonder why she changed her mind.

A . must B. should C. need D. would

3. -Could I borrow your dictionary?

-Yes, of course you_________

A. might B. will C. can D. should

4. I told Sally how to get here, but perhaps I ______ for her.

A. had to write it out B. must have written it out

C. should have written it out D. ought to write it out

5. —Shall I tell John about it?

—No, you ______ . I've told him already.

A. needn't B. wouldn't C. mustn't D. shouldn't

6. ─There were already five people in the car but they managed to take me as well.

─ It______ a comfortable journey.

A. can't be B. shouldn't be

C. mustn't have been D. couldn't have been

7. It's nearly seven o'clock. Jack______ be here at any moment.

A. must B. need C. should D. can

8. .When he was there, he______ go to that coffee shop at the corner after work every day.

A. would B. should C. had better D. might

9. .Sir, you _____ be sitting in this waiting room. It is for women and children only.

A. oughtn't to B. can't C. won't D. needn't

10. The fire spread through the hotel very quickly but everyone ______ get out.

A. had to B. would C. could D. was able to

11. --When can I come for the photos? I need them tomorrow afternoon.

--They _____be ready by 12:00.

A. can B. should C. might D. need

12. .--I stayed at a hotel while in New York.

--Oh, did you? You_ ____with Barbara.

A. could have stayed B. could stay

C. would stay D. must have stayed

13. －Will you stay for lunch?

－Sorry,＿＿＿＿＿ ,My brother is coming to see me.

A. I mustn't B.I can't C. I needn't D.I won't

14. Sorry I'm late. I ______ have turned off the alarm clock and gone back to sleep again.

A. might B. should C. can D. will

15. I should have been there, but I _______ not find the time.

A. would B. could C. might D. should

16. My sister met him at the Grand Theatre yesterday afternoon, so he ___ your lecture.

A. couldn't have attended B. needn't have attended

C. mustn't have attended D. shouldn't have attended

17. --- Are you coming to Jeff's party?

　 --- I'm not sure. I ________go to the concert instead.

　A．must B．would　　 C．should D．might

18. Mr. Bush is on time for everything. How _________ it be that he was late for the opening ceremony?

A．can B．should C．may D．must

19 He hesitated for a moment before kicking the ball, otherwise he ________ a goal.

A．had scored B．scored C．would score D．would have scored

20. —Write to me when you get home.

—_________

A．I must B．I should C．I will D．I can

 

情态动词语法填空：

1. Although Lee's father knew Lee (35)______ receive education, his father wasn't able to afford to send him to school. However, his father's friends helped him pay for his education.

2. Strasser said Lowell got in through the back door, which he kept open at night so that Bonnie (32) _____ get into the backyard.

3. English is the most widely used language in the history of our planet. One in every seven human beings (26) ________ speak it.

4. In my opinion, it is possible for you to find some real good friends with the help of new technology but you (28) ______ ______ take care.

5. Everything we do with our time is a choice. It (35) _____ feel like we "have to" do certain things, but, in reality, we have complete control over how we spend our time.

6. For several weeks she __25__ (ask) me to play chess with her, I suggested a game and she eagerly accepted. It was a school night, however, and at nine o'clock my daughter asked if I __26__ hurry my moves, because she needed to go to bed; she had to get up at six in the morning.

 

1-5 ABCCA 6-10 DCAAD 11-15 BABAB 16-20 ADADC

must could can have to/ought to might had been asking could

 

课后作业

单选：

　1. If I ____ where he lived, I ____ a note to him.

　　 A. knew, would B. had known, would have sent

　　C. know, would send D. knew, would have sent

　2. If they ____ earlier than expected, they ____ here now.

　　 A. had started, would be B. started, might be

　　 C. had started, would have been D. will start, might have been

　3. I didn't know his telephone number. ____ it, I ____ then.

　　 A. Had I known, would ring him up B. Should I know, would have rung him up

　　 C. If I knew; would ring him up D. Had I known; would have rung him up

　4. Mary is ill today. If she _____ , she ____ absent from school.

　　 A. were not ill; wouldn' t be B. had been ill; wouldn't have been

　　 C. had been ill; should have been D. hadn't been ill; could be

　5. Were I to do it, I ________ it some other way.

　　 A. will do B. would do C. would have done D. were to do

　6. I ________ him the answer ________ possible, but I was so busy then.

　　 A. could tell; if it had been B. must have told; were it

　 C. should have told; had it been D. should have told; should it be

　7. Without your help, we________ so much.

　　 A. won ' t achieve B. didn ' t achieve

　　 C. don't achieve D. wouldn't have achieved

　8. You didn't take his advice. ________ his advice, you ________ such a mistake.

　　 A. Had you taken; wouldn't have made B. If you had taken; would make

　　 C. Were you lo take; shouldn t have made D. Have you taken; won t have made

　9. We wish we ____ what you did when we were at high school.

　　 A. did B. could have done C. have done D. should do

　10. She wishes she ____ to the theatre last night.

　　 A. went B. would go C. had gone D. were going

　11. Tom is very short now. His mother wishes that he ________ be tall when he grows up.

　　 A. could B. should C. would D. were able to

　12. My sister advised me that I ________ accept the invitation.

　　 A. could B. must C. should D. might

　13. He asks that he ________ an opportunity to explain why he's refused to go there.

　　A. is given B. must give C. should give D. be given

　14. Do you think of Wang Fang's suggestion that he ________ Mr. Li to the party?

　　 A. will invite B. have invited C. is invited D. invite

　15. I insisted that he ________ at once.

　　 A. be gone B. go C. would go D. might go

　16. Li Ming insisted that he ________ anything at all.

　　A. hadn ' t stolen B. shouldn ' t steal C. doesn ' t steal D. steal

　17. It is quite natural that my coming late again ________ them very angry.

　　 A. had made B. would make C. makes D. make

　18. He acted as if he ________ everything in the world.

　　 A. knew B. knows C. has known D. won't know

　19. Read it aloud so that I ________ you clearly.

　　 A. may hear B. will hear C. hear D. have heard

　20. They got up early in order that they ________ they first train.

　　 A. caught B. will catch C. might catch D. shall catch

 

用所给动词的适当形式填空：

1. If people ______(drive) more slowly, there wouldn't be so many accidents.

2. If you had worked carefully, you _____(not make) so many mistakes.

3. The boat wouldn't have drifted away, if we _____ (tie) it up.

4. If I had known you already _____(have) a typewriter, I _____(not, buy) one for your birthday.

5. If he _____(be) here this afternoon I would go with him.

6. If it were to rain tomorrow, the match _____(postpone).

7. But for your help, we ______(not be) able to finish the work in time.

8. If it _____(not, be) for the leadership of the Party, we would not have achieved so much.

9. I wish I _____(study) hard while I was young.

10. It is about time that fence ______(mend).

11. My request is that we ______(hold) another session to discuss the problem.

12. It is strange that the car _____(break) down at exactly the same place where it _____(break) down yesterday.

13. The baby smiled as if he _____(understand) what his mother _____(say).

14. He talked as if he _____(do) all the work himself, but in fact Tom and I _____(do) most of it.

15. If only we _____(have) a phone! I'm tired of queuing outside the public phone box.

16. ----- "Can we come in late tomorrow?" ----- "I'd rather you _____(come) in on time."

17. He looks as if he _____(be) ill for a long time.

18. He always talks as though he ______(address) a public meeting.

19. If a metal ______(heat), it will expand.

20. I _____(stay) home if it rains this evening.

 

1~5 BADAB 6~10 CDABC 11~15 CCDDB 16~20 ADAAC

1. drove 2. wouldn't have made 3. had tied 4. have / would not have bought

5. should be / were / were to be 6. would be postponed 7. wouldn't have been

8. were not 9. had studied 10. were mended 11. (should) hold

12. should have broken / broke 13. had understood / said

14. had done / did 15. had 16. came 17. had been

18. were addressing 19. is heated 20. will stay

 

 

“双十一”课程活动时间

 

2020年11月5日（周四）-11月15日24点（周日）

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