Book 3 Unit 2 Healthy eating
（一）情态动词+have done用法：
1.must have done
“过去一定发生了/做了某事”，表示对过去事情肯定推测，只用于肯定句中。
It must have rained last night,for the road is quite muddy.
昨晚一定下雨了，因为路很泥泞。
2.can/can’t have done
“过去可能发生了(做了)某事/过去不可能发生了（做了）某事”，表示对过去疑问和否定的推测，用于疑问句和否定句中。
There is nowhere to find Tom. Where can he have gone? He can’t have gone to Beijing, for I saw him just now.
到处都找不到汤姆，他可能去哪里呢？他不可能去北京，我刚刚还见他来。
3.couldn’t have done
“过去不可能做过某事”
1）表示对过去事情的否定推测
We couldn’t have heard them because of the noise from the river.
由于河水的声音我们当时不可能听到他们的谈话。
2）用于虚拟语气
If it hadn’t been for your help, I couldn’t have succeeded.
要是没有你的帮助，我也不可能成功。
4.could have done
“过去本来能做某事而实际上没做”（表虚拟）
Tom could have passed the exam, but he was too careless.
汤姆本来能通过考试，但他太粗心了。
5.may/might have done
“过去可能/也许做了某事”表示对过去发生过的事情的推测，用might 可能性更小。
It is too late. I think Tom may /might have gone to bed.
太晚了，我想汤姆或许已经睡了。
6.may not /might not have done
“过去可能/也许没做过某事”表示对过去发生过的事情推测，用might 可能性更小。
Tom may not have finished his homework.
汤姆可能没完成他的作业。
They might not have regarded me as their friends.
他们可能没把我当朋友看待。
7.should/ought to have done
“过去本应该做某事而实际上没做”
You are too lazy. You should/ought to have finished the work yesterday. 你太懒了，你昨天本应该完成那项工作。
8.shouldn’t /oughtn’t have done
“过去本不应该做某事而实际上却做了”You shouldn’t/oughtn’t have told her the truth. 你本不该告诉她真相。
9.needn’t have done
“过去本来不必做某事但却做了”
You needn’t have taken a taxi here.
你本来不必打车来这里。
（二）情态动词的特殊用法
1. can’t but do sth表示“不得不/只好做某事”
I can’t but tell you the truth.
我不得不告诉你真相。
注意：表示“不得不/只好做某事”的句式：can’t help but do
can’t choose but do
can do nothing but do
2.can’t help doing sth 情不自禁做某事Hearing the sad story, he can’t help crying.
听完那个悲伤的故事, 他禁不住哭了起来。3.may as well do sth 最好/倒不如做某事
You may as well finish your work now.
你最好现在就完成你的工作。
4.may well do sth 相当于be likely to do sth
“很可能做某事”
Tickets are likely to be expensive.
入场券可能很贵。
5.can not /can never +be +adj enough,
can not /can never +be +too adj
“再...也不过分”或“越..越好”
You can never be too careful while crossing the road.
You can never be careful enough while crossing the road.
过马路的时候，你越细心越好。
6.may用于祈使句，表示祝愿
May you succeed！
祝你成功！
7.must 表示“偏要，硬要”
Must you make so much noise?
你非要这么吵吗？
8.should与疑问词连用，表示说话人惊讶、难以相信等。How should I know?
我怎么知道呢？
Why should he think that ?
他怎么那么想呢？
一、选择题 1．It is 11:00 p.m now. Peter hasn't come back yet. His mother ______ be very mad at him. A．may B．can C．must D．need 2．—Have you heard about the temperature of the earth will rise to 59℃ in 2020?—Don’t worry! The news _______ be true. A．must not B．may not C．needn’t D．will not 3．-Listen! A wolf is crying! -It _______ be a wolf, because a wolf never comes out at this time. A．mustn’t B．needn’t C．can’t D．don’t 4．I’ve bought a nice necklace for Jo’s birthday. She _____like it, but I’m not sure. A．can B．may be C．might D．must 5．---Mum, must I finish my homework today? ---No, you . Tomorrow is Sunday and you may have a rest today. A．shouldn’t B．mustn’t C．can’t D．don’t have to 6．You look quite tired. You'd better ________ a good rest. A．stop to have B．stop having C．to stop to have D．to stop having 7．—Tom, we’re going shopping at eight, right? —Yeah, but I ______ be a little late, so don’t wait for me. A．may B．should C．mustn’t 8．You should________ the teacher________being late for school. A．apology to, about B．apologize to, for C．apologies to, for D．apologize to, on 9．—Can you come to my party on Saturday afternoon? —Sorry, I can’t. I ________ meet my friends. A．can’t B．might have to C．needn’t 10．— I wonder if these are Jim's glasses. —They _____his. He doesn't wear glasses. A．might be B．could be C．can't be 11．—The book report is very important. You ________ write it carefully. —But I ________ hand it in now. A．must; must B．have to; must C．must; have to D．have to; have to 12．Even the top student can't work out this problem, so it________ be too difficult. A．must B．may C．can D．need 13．—________ I borrow the books from the library, Miss Yang? —Sorry, you________. These books are only for members of the English Club. A．Can; couldn’t B．Could; can’t C．Could; could n’t D．Can; needn’t
情态动词+ have + done用法 1、“must+have+done”表示对过去事情的肯定推测，译成“_____________”，该结构只用于________。 1). It must have rained last night, for the ground is wet. 翻译： 2). He is playing on the playground, he must have finished his homework. 翻译： 2、“can't/couldn’t+ have+ done”表示对过去事情的否定推测，译成 “___________________”。 1). Mr. Smith can't have gone to Beijing, for I saw him in the library just now. 翻译： 2). Mary can't have stolen your money. She has gone home. 翻译： 3、“could+have+done” 有两种用法，一种表示猜测，“_____________________”，用于疑问句；另一种是虚拟语气，表示对过去事情的假设，意思是________________________。 1）What could have happened? 翻译： 2）He could have passed the exam, but he was too careless. 翻译： 4、“can+have+done”(较少使用)表示对过去行为的怀疑，用于疑问句，译成 “_____________”。 1). There is no light in the room. Can they have gone out? 翻译： 2). There is nowhere to find them. Where can they have gone? 翻译： 5、“may+have+done”表示对发生过的事情的推测，意思是“_______________”，用于肯定句中。 —What has happened to George? —I don't know. He may have got lost. 翻译： 6、“might+have+done”表示对过去事情的推测，might与may意思相同，但可能性更小。多用于虚拟语气结构中。
情态动词全解析 一、何谓“情态动词” 情态动词主要用来表示说话人的情感、态度等，是中学英语语法的重点，也是高考的热点，是单项填空必考的一个知识点。情态动词在近五年高考中主要考查四点：情态动词表示推测和可能性的用法；情态动词与虚拟语气；情态动词的表达“情感、态度、语气等”，情态动词表示“必要性”等方面的用法。 二、情态动词的特点 1.没有人称和数的变化。 2. 有些情态动词有过去式的变化: . will → would , can → could , may→ might , dare → dared 三、情态动词的否定形式 情态动词+ not +动词原形can not: can't , must not: mustn't , need not : needn't 四、情态动词的用法及相互间的区别（注意：这是常考的考点） 1. can , be able to be able to 表示经过努力后, 能够做到; be able to 有多种形式的变化。can 1). 表示体力或脑力方面的能力; 2). 表示允许、可能性。 could 是can的过去式, 表示过去有能力及过去存在的可能性; 用于疑问句表示委婉地提出问题。 1) The fire spread through the hotel very quickly but everyone ____ get out. A. had to B. would C. could D. was able to 2) -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 表示询问或说明一件事可不可做; 表示某事有可能发生。might是may的过去式; 用在疑问中比may委婉、客气。 1) -May I take this book out of the reading-room -No, you mustn't. ( Yes, you may.) 2) -Might I make a suggestion -Yes, you may. 3. must 1). 表示必须要做的事: 必须 2) 表示很有把握的推断: 一定, 准是。have (has)to : have (has)got to 必须, 不得不。过去式: had to 3) -Must I get to the station before three o'clock -Yes, you must. ( No, you needn't. ) 4) I'm afraid you will have to wait a while. 5) She must be in the classroom now. 6) Mary ____ be in Paris, I saw her in town only a few minutes ago. A. mustn't B. shouldn't C. can't D. may not 4. shall 1) 在疑问句中, 用于第一、三人称表示说话人征求对方的意见或向对方请求。 2) 用于二、三人称,表示说话人给对方的命令、警告、允诺等概念。 1) - Shall I place an order with you now -No, you needn’t. -Shall he turn down the radio a bit -
必修三unit2语法讲解情态动词用法（二） 、ought to的用法 1. ought to应该”与should相比较ought to语气重,偏重责任、义务、 道德、法律”等方面，意为应该” ①We ought to stop polluti ng n ature.我们应该停止污染大自然。 2. ought to表示较大的可能性。 ①Mary ought to be here soon.玛丽应该很快就来了。 ［点津］用ought to表示推断时，语气较肯定，通常指的是一种合乎逻辑的 可能性（与should表推断时相似）,有时可译为很可能；准是”语气比must要弱）。 3. ought to的否定形式为ought not to或ought n't to,其一般疑问句形式是将ought置于主语前。 ①We ought not to start so late.我们不该这么晚动身。 4. 在反意疑问句中,常省掉to用ought n't或should n't。 ① He ought to take back what he has said, ought n' t/should n't he? 他应该收回他说的话，是吗？ 1 —1.写出下面句中黑体部分的意义 ① To keep fit, weought to lear n more about our body. _____ ① Youought not to do such a thing. _______ ① Itought to be a close game. _______ 1 —2.用ought完成句子 ①（尔不该责备他。You __________ （scold ）him. ①我明天该动身吗？一_______________ （_leave ［tomorrow? 是的，你应该。一Yes, you ought to ①我们现在应该走，是吗？We ought to go now, ______________ _? 二、have to, don't have to 与must n't 的用法 1. have to（口语中常用have got to）表示客观需要做的事情，意为必须；不 得不”有时态、人称和数的变化，其否定式和疑问式应由助动词do构成。 ① My brother was very ill, so I had to call the doctor in the middle of the ni ght. 我弟弟病了，我不得不半夜里把医生请来。
情态动词+have_done结构 一、“must+have+done” 表示对过去事情的肯定推测，译成“一定做过某事”，该结构只用于肯定句。 1. It must have rained last night, for the ground is wet. 昨晚一定下雨了，因为地面还是湿的。 2. You must have been mad to speak to the servant. 你和仆人说话，一定是发疯了。 二、“can't+have+done” 表示对过去事情的否定推测，译成“不可能做过某事”。 1. Mr. Smith can‘t have gone to Beijing, for I saw him in the library just now. 史密斯先生不可能去北京了，我刚才还在图书馆见过他。 2. Mary can't have stolen your money. She has gone home. 玛丽不可能偷你的钱，她回家去了。
三、“can+have+done” 表示对过去行为的怀疑，用于疑问句，译成“可能做过……吗？”。 1. There is no light in the room. Can they have gone out? 屋里没有灯，他们可能出去了吗？ 2. There is nowhere to find them. Where can they have gone? 到处找不到他们，他们可能到什么地方去呢？ 四、“could+have+done” 是虚拟语气，表示对过去事情的假设，译成“本来能够”做某事而没有做。 1. He could have passed the exam, but he was too careless. 本来他能够通过考试，但是他太粗心。 五、“may+have+done” 表示对过去发生的事情的推测，译成“可能已经”，用于肯定句中。——What has happened to George? ——I don't know. He may have got lost. ——乔治发生了什么事？ ——我不知道，他可能迷路了。
“情态动词+have done”的用法 “情态动词＋have done”表示对过去情况的推测或估计，是历年高考的热点。现就这一语言现象作如下归纳： 1．should (ought to) have＋过去分词 表示过去应该做而（实际）没有做的事情,含有责备或遗憾的语气，意为“本应该……”；其否定形式为“should not／ought not to have ＋过去分词”，表示某种行为不该发生但却发生了。 Mr. White _____ at 8:30 for the meeting , but he didn’t’ show up. （04’广西卷）A. should have arrived B. should arrive C. should have had arrived D. should be arriving [解析]本题中的一个关键词but暗示了“Mr. White按道理理应到了，而他没有到”。故答案选[A]。 2．needn’t have＋过去分词 表示过去没有必要做某事, 但实际上做了某事。 As you worked late yesterday, you_________ h ave come this morning. (06’陕西卷) A. mayn’t B. can’t C. mustn’t D. needn’t [解析] He needn't have come，表示“他本没有必要来（实际却来了）”，根据句意，答案应选[D]。 [注意] He didn't need to come yesterday，意为“他昨天没有必要来（实际也没来）”。3．must have＋过去分词 用于肯定句，表示“过去一定做过某事”，表示一种很有把握的推测。 [注意] 对过去发生情况的否定推测常用can’t／couldn’t have ＋过去分词。
情态动词练习 I. 用适当的情态动词填空。 1. Peter________ come with us tonight, but he isn’t very sure yet. 2. —_______ I do it now? —No, you needn’t. 3. —I heard they went skiing in the mountains last Sunday. —It _____ (not) be true because there was little snow there. 4. It has been announced that all the students________ remain in their seats until five o’clock. 5. It’s nearly eight o’clock. Steven________ be here at any moment. 6. ─Would you come back late next time? ─No, I________. II. 单选题。 1. You________ to the meeting tomorrow if you have something more important to do. A. don’t need come B. shan’t need come C. needn’t come D. needn’t to come 2. She________ to the cinema for I saw her just now. A. mustn’t have gone B. may not go C. can’t have gone D. needn’t go 3. He________ see a doctor before it is too late. A. must B. must have to C. can D. need 4. ─________ I stop here, sir? ─No. Go on to the next paragraph, please. A. Will B. May C. Would D. Ought 5. ─________ we finish all the exercises in class? ─Yes, you________. A. Shall; will B. Need; can C. Can; might D. Must; must
Modal Verbs 情态动词有can (could), may (might), must (must), have to, shall (should), will (would), need (need), dare (dared), ought to 等。情态动词无人称和数的变化。它不能单独使用，必须跟其后的动词原形构成谓语。情态动词的具体用法如下： 一、can, could 1、表示能力。 a. Can you speak English? b. Can you finish this work tonight? c. Man cannot live without air. Note:
(1) can表示能力时，可用be able to 代替。 a. I’ll not be able to come this afternoon. (2) 当我们要表示“某件事情已经 成功”时，应用was/ were able to , 不能用could a. He saw well and he was able to swim to the river when the flood happened. b. He was able to go to the party yesterday evening and he enjoyed himself very much. 2、表示客观可能性
a. People who live near airports can have their hearing harmed. b. The boy can sometimes be very naughty. （表示某人或某物一时的情况，“有时会。。。”） c. The invention can be improve d. d. Even experts can make mistakes. e. He can’t be in Beijing now because I saw him a moment ago. f. He had a lot of work to do last night, so he couldn’t have gone to see a film. Note: 在肯定句中用can表示可能性时，其含义是理论上的可能性，不表示
情态动词+have+done是历年高考的重点和难点之一，现将其用法总结归纳如下： 一、must+have+done表示对过去事情的肯定推测,译成“一定做过某事”,该结构只用于肯定句. 1. It must have rained last night, for the ground is wet. 昨晚一定下雨了，因为地面还是湿的 2. You must have been mad to speak to the servant.你和仆人说话,一定是发疯了 二、“can't+have+done”表示对过去事情的否定推测，译成“不可能做过某事”。 1. Mr. Smith can't have gone to Beijing, for I saw him in the library just now. 史密斯先生不可能去北京了，我刚才还在图书馆见过他。 2.Mary can't have stolen your money. She has gone home.玛丽不可能偷你的钱,她回家去了 三、“can+have+done”表示对过去行为的怀疑，用于疑问句，译成“可能做过……吗？”。 1.There is no light in the room. Can they have gone out?屋里没有灯,他们可能出去了吗? 2. There is nowhere to find them. Where can they have gone? 到处找不到他们，他们可能到什么地方去呢？ 四、could+have+done’是虚拟语气,表示对过去事情的假设,意思是本来能够做某事而没有做. He could have passed the exam, but he was too careless.本来他能通过考试，但他太粗心 五、“may+have+done”表示对发生过的事情的推测，意思是“可能已经”或“也许已经”，用于肯定句中。—What has happened to George? —I don't know. He may have got lost. —乔治发生了什么事？ —我不知道，他可能迷路了。 六、“might+have+done”表示对过去事情的推测，might 与may意思相同，但可能性更小。多用于虚拟语气结构中。 1. He might have given you more help, even though he was busy. (MET90) 他或许会多给你一些帮助，即使他很忙。 2. She might have achieved greater progress, if you had given her more chances. 如果你多给她点机会，她可能已经取得更大的成绩。 七、“would+have+done”虚拟语气，表示对过去事情的假设，意思是“本来会做”。 1. I would have told you all about the boy's story, but you didn't ask me. 我本来会告诉你这个小男孩的故事，但是你没有问我。 2. Without your help, I wouldn't have achieved so much. 没有你的帮助，我是不会取得如此大的成绩。 八、“should+have+done”意思是“本来应该做某事，而实际没做。” “shouldn't+have+done”表示本来不应该做某事,而实际做了.含有指责对方或自责的含意 1. Tom, you are too lazy. The work should have been finished yesterday. 汤姆，你太懒惰了，这项工作本来应该昨天就做完的。 2. Look, Tom is crying. I shouldn't have been so harsh on him. 看，汤姆哭了，我本来不应该对他如此严厉。 九、“ought to+have+done”表示过去应该做而实际并没有做，译成“理应做……”，往往表示遗憾。与 “should+have+done”用法基本一样。 I ought to have gone home last Sunday. 我理应上星期日回家。 You ought not to have given him more help. 你不应该帮助他那么多。 十、“need+have+done”表示本来需要做某事而没有做。“needn't+have+done”则表示“本来不需要做某事而做了”。 I needn't have bought so much wine—only five people came. 我本来没有必要买这么多酒，只来了五个人。 He need have hurried to the station. In that case, be wouldn't have missed the train. 他本来需要快点去车站，那样的话，他就不会误了火车。 “情态动词＋have done”表示对过去情况的推测或估计，是历年高考的热点。 1．should (ought to) have＋过去分词 表示过去应该做而（实际）没有做的事情,含有责备或遗憾的语气，意为“本应该……”；其否定形式为“should not ／ought not to have＋过去分词”，表示某种行为不该发生但却发生了。 Mr. White _____ at 8:30 for the meeting , but he didn’t’ show up.（04’广西卷） A.should have arrived B.should arrive C.should have had arrived D.should be arriving [解析]本题中的一个关键词but暗示了“Mr. White按道理理应到了，而他没有到”.故答案选[A] 2．needn’t have＋过去分词表示过去没有必要做某事, 但实际上做了某事。 As you worked late yesterday, you_________ have come this morning.(06’陕西卷) A. mayn’t B. can’t C. mustn’t D. needn’t [解析] He needn't have come，表示“他本没有必要来（实际却来了）”，根据句意，答案应选[D]。 [注意] He didn't need to come yesterday，意为“他昨天没有必要来（实际也没来）”。 3．must have＋过去分词用于肯定句,表示‘过去一定做过某事’,表示一种很有把握的推测 [注意] 对过去发生情况的否定推测常用can’t／couldn’t have ＋过去分词。 I have lost one of my gloves. I ________ it somewhere .（05’北京春季） A. must drop B. must have dropped C. must be dropping D. must have been dropped [解析]本题应选B。本题的前一句说明一个结果，后一句则表示一个原因。 I ____have been more than six years old when the accident happened.(05’天津卷) A. shouldn't B. couldn't C. mustn't D. needn't [解析]从题意上分析，本题的前一句陈述一个理由，后一句则是由前一句得出的结论。故本题选[b] 。 4．may／might have＋过去分词表示对过去情况的一种不太有把握的可能性推测，表示“过去可能／大概已做了某事”；否定句表示“过去可能还没有做某事”。 We have proved great adventurers, but we have done the greatest march ever made in the past ten years. (06’天津卷) A. needn’t B. may not C. shouldn’t D. mustn’t Key:[b] 5．can／could have＋过去分词 表示“过去本来可以做某事，但实际上没有做”；否定句表示“不可能已做了某事”；疑问句表示“可能／也许已做了某事吗？”。 --- 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 Key: [A] 巩固性练习：从A、B、C、D中选择最佳答案。 1．---You didn’t wait for Mr. Smith last night, did you? ---No, but we ______. He didn’t return home at all. A. couldn’t have waited B. needn’t have C. didn’t need to D. should wait 2．Harry ______ have won the Physics competition easily yesterday, but he gave up. A. could B. might C. should D. must 3．---May I speak to your manager Mr. Smith at six o’clock tonight ?” 1
英语情态动词的用法大全附解析 一、初中英语情态动词 1．—We've got everything ready for the picnic. —Do you mean I __________ bring anything with me? A. can't B. mustn't C. couldn't D. needn't 【答案】 D 【解析】【分析】句意：—我们已经为野餐准备好了一切。—你的意思是我不必带任何东西吗？A. can't 不能；B. mustn't 表示禁止，一定不要；C. couldn't不能，表示过去时态；D. needn't不必。结合句意，故选D。 【点评】本题考查情态动词的用法。 2．—How amazing this robot is! —Wow, it has video cameras in its eyes, so it “see” and interact with pe ople. A. may B. can C. must D. should 【答案】 B 【解析】【分析】句意：—这个机器人多么惊人啊！—哇，在它的眼睛里有摄像机，因此它能看见和人打交道。A. may 可以，可能；表示许可，B. can 能；表示能力，C. must 必须；D. should应该；根据it has video cameras in its eyes,可知是有能力看见，故选B。 【点评】考查情态动词辨析。熟记情态动词的含义和用法。 3．—Where is George? —He _______ be here just now. His coffee is still warm. A. need B. can't C. must D. shouldn't 【答案】 C 【解析】【分析】句意：——乔治在哪里？——他刚才一定在这里，他的咖啡还是热的。A. need需要； B. can't 不能，不可能（表示推测）； C. must 必须，一定（表示推测）； D. shouldn't不应该；根据His coffee is still warm.可知表示肯定推测一定在这儿；故答案为C。 【点评】考查情态动词。掌握情态动词表推测时的意义和用法。 4．— Sorry, I forgot to take money with me. Maybe I can't buy the book you like. — Mum, you ______ worry about it. We can pay by Alipay （支付宝）. A. can't B. needn't C. mustn't D. shouldn't 【答案】 B 【解析】【分析】句意：——对不起，我忘记带钱了。也许我不能买你喜欢的书。——妈妈，你不用担心。我们可以用支付宝支付。A. can't不能，指不允许或否定推测；B. needn't 不需，指没必要；C. mustn't不能，表禁止；D. shouldn't不应该，表建议。根据句意语境，本句是说妈妈不需要担心，故答案为B。 【点评】考查情态动词。理解句意并掌握情态动词的意义和用法区别。
情态动词+have+done 一、“must+have+done”表示对过去事情的肯定推测，译成“一定做过某事”，该结构只用于肯定句。 1. It must have rained last night, for the ground is wet. 昨晚一定下雨了，因为地面还是湿的。 2. You must have been mad to speak to the servant. 你和仆人说话，一定是发疯了。 二、“can't+have+done”表示对过去事情的否定推测，译成“不可能做过某事”。 1. Mr. Smith can't have gone to Beijing, for I saw him in the library just now. 史密斯先生不可能去北京了，我刚才还在图书馆见过他。 2. Mary can't have stolen your money. She has gone home. 玛丽不可能偷你的钱，她回家去了。 三、“can+have+done”表示对过去行为的怀疑，用于疑问句，译成“可能做过……吗？”。 1. There is no light in the room. Can they have gone out? 屋里没有灯，他们可能出去了吗？ 2. There is nowhere to find them. Where can they have gone? 到处找不到他们，他们可能到什么地方去呢？ 四、“could+have+done”是虚拟语气，表示对过去事情的假设，意思是本来能够做某事而没有做。 He could have passed the exam, but he was too careless. 本来他能够通过考试，但是他太粗心。 五、“may+have+done”表示对发生过的事情的推测，意思是“可能已经”或“也许已经”，用于肯定句中。 —What has happened to George? —I don't know. He may have got lost. —乔治发生了什么事？ —我不知道，他可能迷路了。 六、“might+have+done”表示对过去事情的推测，might与may意思相同，但可能性更小。多用于虚拟语气结构中。 1. He might have given you more help, even though he was busy. (MET90) 他或许会多给你一些帮助，即使他很忙。 2. She might have achieved greater progress, if you had given her more chances. 如果你多给她点机会，她可能已经取得更大的成绩。 七、“would+have+done”虚拟语气，表示对过去事情的假设，意思是“本来会做”。 1. I would have told you all about the boy's story, but you didn't ask me. 我本来会告诉你这个小男孩的故事，但是你没有问我。 2. Without your help, I wouldn't have achieved so much. 没有你的帮助，我是不会取得如此大的成绩。 八、“should+have+done”意思是“本来应该做某事，而实际没做。” “shouldn't+have+done”表示本来不应该做某事，而实际做了。含有指责对方或自责的含意。 1. Tom, you are too lazy. The work should have been finished yesterday. 汤姆，你太懒惰了，这项工作本来应该昨天就做完的。 2. Look, Tom is crying. I shouldn't have been so harsh on him. 看，汤姆哭了，我本来不应该对他如此严厉。 九、“ought to+have+done”表示过去应该做而实际并没有做，译成“理应做……”，往往表示遗憾。与“should+have+done”用法基本一样。 I ought to have gone home last Sunday. 我理应上星期日回家。 You ought not to have given him more help. 你不应该帮助他那么多。 十、“need+have+done”表示本来需要做某事而没有做。“needn't+have+done”则表示“本来不需要做某事而做了”。 1.I needn't have bought so much wine—only five people came. 我本来没有必要买这么多酒，只来了五个人。 2.He need have hurried to the station. In that case, be wouldn't have missed the train. 他本来需要快点去车站，那样的话，他就不会误了火车。
英语情态动词用法详解 一、单项选择情态动词 1．Look! There are so many mistakes in your composition. You ________ have fixed full attention on it. A．can B．should C．need D．might 【答案】B 【解析】 【详解】 考查情态动词。句意：看！你的作文里有那么多的错误。你本应该把所有的注意力都集中在它上面的。表示“本应该做但实际上没有做”应该用should have done结构，can have done 表示可能；need表示需要；might have done表示可能做过某事；故选B。 2．---Hi, Johnson, any idea where Susan is? ---It is class time, so she __________ in the classroom now. A．can be B．must have been C．might have been D．should be 【答案】D 【解析】 考查情态动词的用法。A. can be可能，可以是；B. must have been一定（对过去事实肯定的推测）；C. might have been可能（对过去事实肯定的推测）；D. should be应该是。句意：—知道苏珊在哪里吗？—现在是上课时间，她应该在教室里。故答案选D。 3．The room is so clean. He ________ have cleaned it yesterday evening. A．will B．need C．can D．must 【答案】D 【解析】 【详解】 考查情态动词表推测。句意：房间如此干净，他一定是昨天晚上打扫过了。must have done 表示对过去发生的事情有把握的猜测，意思是“一定（做过）”，故D项正确。 4．— Excuse me, do you mind if I open the window? — Well, if you __________. I can put on more clothes. A．can B．may C．must D．shall 【答案】C 【解析】
Ⅰ.用适当的情态动词填空 1．When you cross the street, you must be careful with the passing cars. 2．It can’t be his mother, for she has been ill at home for a long time. 3．We enjoy good weather in January, but sometimes it can be terribly cold. 4．I may come to the party with you, but I am not sure. 5．When he was young, he would climb the small hill every morning. 6．—May I take this seat? —Yes, you may/can． 7．Tom comes from Australia, so he can speak English very well. 8．If you can pass the driving test, you shall get a new car. Ⅱ.单项填空 1．—I heard they went skating in the mountains last winter. —It ________ be true because there was little snow there. A．may not B．won’t C．couldn’t D．mustn’t 解析：选C。句意：“我听说他们去年冬天去山区滑雪了。”“那不可能是真的，因为那里几乎没有雪。”couldn’t“不可能”，表示有把握的否定推测。may not“可能不”，与语境不符；won’t“不会”；mustn’t“禁止”。 2．— I haven’t got the reference book yet, but I’ll have a test on the subject next month. — Don’t worry. You ________ have it by Friday. A．shall B．could C．must D．may 解析：选A。句意：“我还没拿到参考书，下个月我要参加这门科目的考试。”“别担心。周五之前你会拿到。”shall用于第二、三人称，表示允诺、威胁、警告等。 3．— Could I use your computer while you are out? — Of course you ________． A．could B．should