专题03 情态动词和虚拟语态

情态动词

★ 情态动词：can, could, may, might, must, ought to, shall, will, would, need ,dare

1. 表示推测的情态动词

1.1基本原则：

1.1.2 对现在或将来情况推测，用情态动词+do / be / be doing…

对过去的推测，用情态动词+have done / been…

1.1.3表示肯定推测的情态动词,按可能性由大到小依次为:must> should / ought to>may>might>could

1.1.4否定推测，按语气由强到弱依次为： can’t / couldn’t（根本不可能）>may not> might not/could not(可能不)。 

1.2 具体用法：

1.2.1 must be表示推测，意为“一定是……”                     只用于肯定句中

must have done意为“一定做过某事或某事肯定发生了”      并且有前文铺垫

e.g. Listen! There must be some children in the room.

  The road is wet. It must have rained last night.

1.2.2 should (not) / ought (not) to在中表示根据常规或常识推测，表示“某事应该或不应该发生”

      e.g. It is nearly 7 o’clock. Jack should be here at any moment.

          You shouldn’t be texting in the class now. We are having a lesson.

(should not 含有责备之意)

1.2.3 can, could表达推测时，一般用于疑问句和否定句中；can用于肯定句中表示一种理论上的可能性，意为“有时候会…”，并不牵涉是否真的会发生；could用于肯定句中，语气比may/ might更弱。

      e.g. It is usually warm in my hometown in March, but it can be rather cold sometime.        

1.2.4 may (not) / might (not)表达一种不太把握的推测，意为“或许，可能”；might的语气比may较婉转。

      e.g.  Although this may sound like a simple task, great care is needed.

2. 表达虚拟语气的情态动词

  2.1 适用情况：对过去的一种结果的假设或虚拟，形式：情态动词+have done

  2.2 具体用法：

    2.2.1 should (not) / ought (not) to have done本（不）应该做某事，但却没有做或做了，含有责备或后悔之意。

     e.g. You should have gone over your lesson yesterday. (In fact, you didn’t go over your lesson yesterday.)

2.2.2 could have done本来能够做某事但未做。

  e.g. If you followed my advice, you could have finished it.  比较一下这一句：

     The road isn’t wet. It couldn’t/ can’t have rained last night. (对过去的猜测)

2.2.3 needn’t have done: 本没有必要做某事但却做了。

needn’t do: 没有必要去做某事 (时间上应该是现在或将来)。

      e.g. —Catherine, I have cleaned the room for you.

—Thanks. You needn’t have done it. I could manage it myself.

You needn’t do it. I’ll do it later.

2.2.4 would (not) have done:本来(不)会发生某事，但却（发生了）或没有发生。常用于虚拟条件句或含蓄虚拟条件引导的虚拟语气，表示对过去所发生事情结果的假设。

     e.g. He hesitated for a moment before kicking the ball, otherwise, he would have scored a goal.

2.2.5 might have done:本来可能发生，但实际上没有发生的事。

     e.g. What a pity! Considering his ability and experience, he might have done better.

3.表达“情感、态度、语气”的情态动词

 3.1 must: 表示主观的义务和必要,意为“必须…”。用于：

肯定句：You must finish it now.                                   

Yes, you must/have to.

疑问句：Must I finish it now?      

No, you needn’t/ don’t.

       条件句或疑问句: 可以用来表示责备、抱怨的感情色彩，意思为“偏要，硬要”

        e.g. —May I smoke here ?
—If you must, choose a seat in the smoking section.

           John, look at the time. Must you play the piano at such a late hour?

3.2 mustn’t: 表示禁止

  e.g. When I was young, I was told that I mustn’t play with matches

3.3 should

3.3.1表示责任和义务。

e.g. According to the air traffic rules, you should switch off your mobile phone before boarding.

3.3.2在虚拟条件句中用以加强假设语气，表示与将来事实相反的假设,意为“万一”。

e.g. If it should rain tomorrow, I would stay at home.万一明天下雨的

Should you be fired, your health care and other benefits will not be immediately cut off.

3.3.3表示说话人对某事不能理解、赶到意外，译为“竟然”。

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

   3.4  shall

3.4.1用于第一和第三人称，常用于疑问句中，用来征求对方意见。

  e.g.  Shall I carry it for you?

3.4.2用于第二和第三人称，表示“命令、威胁、警告、允诺、”等。

e.g. —Excuse me. But I want to use your computer to type a report.

—You shan’t have my computer if you don’t take care of it .

3.4.3用于宣布法律、规定的要求。

e.g.—What does the sign over there read?

 —“No person shall smoke or carry a lighted cigarette，cigar or pipe in this area.”

  3.5 can

3.5.1表示惊异、怀疑、不相信的态度，主要用于否定句、疑问句或感叹句中。

e.g. How can you say that you really understand the whole story if you have only covered only part of the article?

3.5.2表示请求或许可。

e.g. —Mum, I’ve been studying English since 8 o’clock. Can I go out and play with Tom for a while?

—No, I’m afraid not. Besides, it’s raining outside now.

 3.5.3表达一般的或永久的能力。

区别：be able to也可表达能力，但常用来表达在某件事情中所表现出来的能力，尤指克服困难能够完成某事。

e.g. If it were not for the fact that she can’t sing, I would invite her to the party.
          The fire spread through the hotel very quickly but everyone was able to get out.

3.6  would

3.6.1 will与would

3.6.1.1表示意愿: will 表示现在的意愿，would表示过去的意愿。

e.g.  Go where you will.

If you will allow me, I will see you home. (will可用于条件句中表意愿)

He wouldn’t help me yesterday.

I wouldn’t go. （would用于表现在的意愿时语气较委婉）

3.6.1.2表示征求意见或提出请求，主要用于第二人称的疑问句中，would的语气更委婉。     

e.g.  Won’t you take off your coat?

Would Sunday night suit you?

3.6.1.3. 表示习惯和倾向性:will表示现在的习惯，would表示过去的习惯。

e.g. Oil will float on water.

This window won’t open.

When he was a child, he would often go skiing.

That’s just like him—he would lose his keys! 他就是这样，老丢钥匙!

(这里would表示经常发生的令人不耐烦的事)

3.6.1.4. 表示推测：will用于谈论现在，would可用于谈论过去，也可用于谈论现在(语气较委婉)。

e.g. Ask him. He will know. 他可能知道吧。

You wouldn’t know how much she loves him.你可能不知道…

Every family would have some sort of trouble. 家家都会有本难念的经。

You will have heard of it. 你已经听到那事了吧。

I thought you would have finished it by now.

(后接完成式，表示对过去可能已经发生的情况进行推测)

3.6.1.5. 表示执意或决心：will表示现在的执意和决心，would表示过去的执意和决心。

e.g. “Tell me the secret.” “I won’t.” 我才不会！

He would do it, though I told him not to. 虽然我叫他不要做，可是他偏要做。

3.6.1.6. 其他用法

will 还可表示许诺、指示、叮嘱等，

would还可用于评论某一特定的行为等。

e.g. You will have your share. 你会得到你那一份的。

You will do as I told you. 你得照我说的去做。

That’s just what he would say. 他就是爱那样讲话。

You would never do anything to hurt me. 你绝不会做伤害我的事的。

3.6.2 would与虚拟条件句:有时用would，可视为是省略了包含有相关条件的虚拟语气。

e.g. I might see her personally. It would be better.

=It would be better if I saw her personally. 我可能亲自去看她，那样更好些。

She’d be stupid not to accept.

=She would be stupid if the didn’t accept. 她不接受那才笨呢。

3.6.3 would 与used to 表达过去的习惯性的动作或状态

e.g. When he was there, he would / used to go to that coffee shop at the corner after work every day.

3.7 dare 与need

  3.7.1 dare作为情态动词仅用于：

否定句：He dare not go himself.

一般疑问句: Dare you walk through the forest at night?

条件状语从句: If the enemy dare enter the village, we’ll fight against them.

含有表示怀疑词的名词从句：I wonder how the dare say such things.

3.7.2 need作为情态动词仅用于：

  否定句：You needn’t return your book now.

一般疑问句：Need he go there yesterday?

   表对过去的责备：need have/ haven’t done

3.7.3 两者皆可作为实义动词。

虚拟语气

1）概念

  虚拟语气用来表示说话人的主观愿望或假想，所说的是一个条件，不一定是事实，或与事实相反。

2）在条件句中的应用
  条件句可分为两类，一类为真实条件句，一类为非真实条件句。非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。

1.1    真实条件句

真实条件句用于陈述语气，假设的情况可能发生，其中 if 是如果的意思。
　　　时态关系
句型： 条件从句　　　 主句
　　 一般现在时　　 shall/will + 动词原形
　If he comes, he will bring his violin.

典型例题
　The volleyball match will be put off if it ___.　
A.　will rain　 B. rains　 C. rained　 D. is rained
　答案B。真实条件句主句为将来时，从句用一般现在时。注意：
1） 在真实条件句中，主句不能用be going to表示将来，该用shall, will.
　(  ) If you leave now, you are never going to regret it.
　(  ) If you leave now, you will never regret it.
2） 表示真理时，主句谓语动词便不用shall (will) +动词原形，而直接用一般现在时的动词形式。

1.2    非真实条件句

1）时态：可以表示过去，现在和将来的情况。它的基本特点是时态退后。
a.　 同现在事实相反的假设。
句型 ： 条件从句　　　　　主句
　　　　一般过去时　　　should( would) +动词原形
e.g. If they were here, they would help you.

b.　 表示于过去事实相反的假设。
句型： 条件从句　　　　　 主句　　　　　
　　　过去完成时　　　 should(would) have+ 过去分词
e.g. If she had worked harder, she would have succeeded.　　
　 The rice would not have been burnt if you had been more careful.　
　 If my lawyer had been here last Saturday, he would have prevented me from going.
　 If he had come yesterday, I should / would have told him about it.
　 含义：He did not come yesterday, so I did not tell him about it.
　 If he had not been ill and missed many classes, he would have made greater progress.
　 含义： He was ill and missed many lessons, so he did not make greater progress.　

c.　 表示对将来的假想
　句型：　 条件从句　　　　　　 主句
　　　　 一般过去时　　　　　 should+ 动词原形
　　　　 were+ 不定式　　　　 would + 动词原形
　　　　 should+ 动词原形
　If you succeeded, everything would be all right.
　If you should succeed, everything would be all right.
　If you were to succeed, everything would be all right.

1.3 错综句

主句与从句的动作发生在不同的时间，这时主，从句谓语动词的虚拟语气形式因时间不同而不同，这叫做混合条件句。
　　If you had asked him yesterday, you would know what to do now.
　 （从句与过去事实相反，主句与现在事实相反。）
　　If it had rained last night (过去), it would be very cold today (现在).

1.4   虚拟语气倒装

虚拟条件句的从句部分如果含有were, should, 或had, 可将if省略，再把were, should或had 移到从句句首，实行倒装。
　 Were they here now, they could help us.
　=If they were here now, they could help us.
　 Had you come earlier, you would have met him
　=If you had come earlier, you would have met him.　
　 Should it rain, the crops would be saved.
　=Were it to rain, the crops would be saved.

注意：
　 在虚拟语气的从句中，动词'be'的过去时态一律用"were"，不用was， 即在从句中be用were代替。
　 If I were you, I would go to look for him.
　　 如果我是你，就会去找他。
　 If he were here, everything would be all right.
　　 如果他在这儿，一切都会好的。

典型例题
　_____ to do the work, I should do it some other day.
A. If were I　　 B. I were　C. Were I　D. Was I
　 答案C. 在虚拟条件状语中如果有were, should, had这三个词，通常将if省略，主语提前, 变成 were, should, had +主语的形式。但要注意，在虚拟条件状语从句中，省略连词的倒装形式的句首不能用动词的缩略形式。如我们可说 Were I not to do., 而不能说 Weren't I to do.

1.5  wish的用法

用于wish后面的从句，表示与事实相反的情况，或表示将来不太可能实现的愿望。其宾语从句的动词形式为：

　　　　　　　　　　　　　 真实状况　wish后　　　　 　
从句动作先于主句动词动作　　现在时　　过去时
  （be的过去式为 were）　　　　　　　　　　　　　　　 　
从句动作与主句动作同时发生　过去时　　过去完成时
  （had + 过去分词）　　　　　　　　　　　　　　　　　　
将来不大可能实现的愿望　　　将来时　would/could +动词原形
I wish I were as tall as you.　我希望和你一样高。
He wished he hadn't said that. 他希望他没讲那样的话。
I wish it would rain tomorrow. 我希望明天下雨就好了。

2）Wish to do表达法。
　 Wish sb. / sth. to do
　 I wish to see the manager. = I want to see the manager.
　 I wish the manager to be informed at once. (= I want the manager to be informed at once.)

1.6  比较if only 与 only if

only if表示"只有"；if only则表示"如果……就好了"。If only也可用于陈述语气。
　I wake up only if the alarm clock rings. 只有闹钟响了，我才会醒。
　If only the alarm clock had rung.　　　当时闹钟响了，就好了。
　If only he comes early.　　　　　　　但愿他早点回来。

1.7  It is (high) time that

It is (high) time that 后面的从句谓语动词要用过去式或用should加动词原形，但should不可省略。
　 It is time that the children went to bed.
　 It is high time that the children should go to bed.

1.8 need "不必做"和"本不该做"(其他情态动词虚拟教师自己扩展)

didn't need to do表示： 过去不必做某事, 事实上也没做。.
　needn't have done表示： 过去不必做某事, 但事实上做了。
　John went to the station with the car to meet Mary, so she didn't need to walk back home. 约翰开车去车站接玛丽，所以她不必步行回家了。
　John went to the station with the car to meet Mary, so she needn't have walked back home. 约翰开车去车站接玛丽，所以她本不必步行回家了。 (Mary步行回家，没有遇上John的车。)

典型例题
　There was plenty of time. She ___.
A. mustn't have hurried　 B. couldn't have hurried　　C. must not hurry　 D. needn't have hurried
　答案D。needn't have done. 意为"本不必"，即已经做了某事，而时实际上不必要。
　Mustn't have done 用法不正确，对过去发生的事情进行否定性推断应为couldn't have done, "不可能已经"。 must not do 不可以（用于一般现在时）。

1．（2022·天津市滨海新区塘沽第一中学高三阶段练习）— You burned your face and arms.

—Yes, I             in the shade like all the other tourists at noon.

A．should be B．must have been C．must be D．should have been

2．（2022·天津河北·高三期中）When reading The Road Not Taken, one cannot help but ________ in one’s mind images of a peaceful wood deep within the countryside.

A．seeing B．to see C．see D．seen

3．（2022·天津市双菱中学高三期中）Your cousin ________ his trip in Jixian County, didn’t he? He looks amazingly different.

A．will have enjoyed B．should have enjoyed

C．can have enjoyed D．must have enjoyed

4．（2022·天津·南开中学高三期中）Walking alone in the deserted town, John felt his blood running cold. He thought he _________ Tom to go with him.

A．might ask B．should ask C．should have asked D．might have asked

5．（2022·天津市西青区杨柳青第一中学高三阶段练习）— Oh, my God! I just missed the last bus back home.

—That’s really bad. I’m sure you         it, but you just didn’t hurry up.

A．should have caught B．could have caught C．could catch D．can catch

6．（2022·天津市双菱中学高三阶段练习）—Few of my fellows passed the politics quiz this time on campus.

—How come? It ________ tough.

A．should be B．might be

C．must have been D．could have been

7．（2022·全国·高三名校集）Technology is supposed to make our lives easier, but it ________ also be frustrating at times.

A．must B．can C．will D．should

8．（2022·全国·高三名校集）Her round figure, seen in the Tang Dynasty, ________ the admirable image.

A．would have been considered B．would have considered

C．had considered D．must have been considered

9．（2022·全国·高三名校集）In the new TOFEL test, there are questions ________ test takers ________ read, listen and then speak into a microphone.

A．which … must B．which … need

C．where … must ` D．where … need

10．（2022·陕西·西北工业大学附属中学高三阶段练习）Mr. Baker, some students want to see you. ________ they come in right now?

A．May B．Should C．Shall D．Will

11．（2022·新疆石河子一中高三阶段练习）If he had not gone out in the storm, he ________ alive now.

A．will be B．would be C．would have been D．is

12．（2022·天津一中高三阶段练习）At the routine office meeting, the headmaster insisted the problems ______ paid special attention to.

A．referred to being B．referred to be C．refer to being D．refer to be

13．（2022·全国·高三名校集）It is essential that these application forms ________ back as early as possible.

A．are sent B．be sent C．will be sent D．should send

14．（2022·全国·高三名校集）If he ________ to the teacher attentively yesterday, he ________ the answer to the problem now.

A．had listened; would have known B．listened; would know

C．listened; would have known D．had listened; would know

15．（2022·全国·高三名校集）________ the traffic jam on the highway, we should have arrived at the stadium earlier.

A．In spite of B．Because of C．But for D．Due to

16．（2022·全国·高三名校集）Sorry, I am too busy at the moment. If I ________free, I would certainly go for a walk with you.

A．have been B．had been C．am D．were

17．（2022·全国·高三名校集）The professor insisted that his solution________more practical and that we________it into practice as soon as possible.

A．was; put B．was; must put C．should be; put D．should be; put

18．（2022·全国·高三名校集）Look at the situation I’m in. If only I ________ your advice earlier!

A．took B．would take C．had taken D．should take

19．（2022·全国·高三名校集）--- I’ve told Jenny the truth about the new house.

---But I’d rather you ________.

A．didn’t B．hadn’t C．don’t D．wouldn’t

20．（2022·全国·高三名校集）If the ambulance had come here sooner last night, the patient ________now.

A．will be alive B．will have been alive C．would have been alive D．would be alive