山西省灵丘县第四中学 人教新课标高一英语下学期必修3第2单元
Unit 2 Healthy eating Period 4 Grammar
情态动词+have done的用法 1．表示对过去事情的推测或估计。
(1)情态动词must＋have done只用于肯定句中，表示对过去发生的事情或状态进行的肯定推测，意为“过去一定做过某事”。
It must have rained last night, for the road is wet. 昨天晚上一定是下雨了，因为路还湿着。 You must have seen the film the Gold Rush. 你肯定看过电影《淘金热》。
注意：表过去“不可能做了”不能用mustn't have done。
(2)can't have done /couldn't have done表示对过去发生的事情或状态的否定的推测，意为“过去不可能做过，肯定没做过”。
My sister met him at the theatre last night, so he couldn't have attended your lecture. 我姐姐昨天晚上在电影院遇见他了，所以他肯定没参加你的演讲。
(3)can/could have done用于疑问句中表示对过去发生的事情或状态的不太有把握的推测，常表示“过去可能做过吗？”。
I can't find Tom anywhere in the office building.Where can he have gone? 我在办公楼任何地方都找不到汤姆。他有可能去了哪里了呢？ 注意：表推测的情态动词只有can/could常用于疑问句中。
(4)may/might＋have done表示对已发生的动作或存在的状态进行不确定的推测，表示“过去可能做过某事”， might语气比may稍弱。多用于肯定句。 You might have read about it in the papers. 你可能在报上已经看过这个消息了。
She didn't get there in time.She may have missed the bus. 她没能及时到达那儿。她可能没赶上公共汽车。 2．表示对过去所发生事情的一种遗憾或责备的语气。
(1)should/ought to＋have done 表示“过去本该做而没做”。其否定形式为：shouldn't/oughtn't to＋have done “过去不该做的事却做了”。
I should have studied hard, but it was too late. 我本该努力学习的，但为时太晚了。 I oughtn't to have lied to you the other day. 那一天我不该跟你撒谎的。
(2)could＋have done “本来能够做的事却没做”。
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山西省灵丘县第四中学 人教新课标高一英语下学期必修3第2单元
He could have solved the problem. 他本来可以解决那个问题的。
The football team could have won the game. 这个足球队本来可以赢得比赛。
(3)needn't have done “原本不必做的事却做了”。
Your home is not far from your school, so you needn't have left in such a hurry. 你家离学校不远，你本不必急着走。
You needn't have watered the flowers, for it is going to rain. 你本不必浇花，因为天快要下雨了。 总结
1. “情态动词＋have done”可表示对过去发生的事情或状态进行推测，如“must have done”、“can't have done”、“may have done”和“might have done”等。
2. “情态动词＋have done”可表示对过去发生的事情表示遗憾或责备，如“should (not) have done”、“ought (not) to have done”和“needn't have done” 等。 3. “情态动词＋have done”还用于虚拟语气中。
4. 表示推测的用法：can, could, may, might, must 皆可表示推测 1、情态动词+动词原形：表示对现在或将来的情况推测 不同的“肯定”程度可按下列层次排列： He is at home. (事实)
He must be at home.（非常肯定的推断） He could be at home.（很可能） He ought to be at home.（很可能） He may be at home.（仅仅可能而已） He might be at home.（或许, 非常不确定） He might not be at home.（也许不在家） He may not be at home. （比might可能） He couldn’t be at home.（很可能不在家） He can’t be at home.（一定不在家） He isn't at home.（事实）
2、情态动词+have done：表示对过去情况的推测
should /ought to have done本来应做而未做，表达遗憾感情色彩
如：I told Sally how to get there, but perhaps I should have written it out for her. may/might have done可能已做 / must have done 一定已做/can’t have done不可能做 如：---Where is my pen? --- I must have lost it.
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山西省灵丘县第四中学 人教新课标高一英语下学期必修3第2单元
could have done指本来能做而实际未做，表达遗憾的感
如：You could at least have sent five cards.你本来可以至少寄去5张明信片的。（说明没有寄那么多） 例题剖析
?Had they known what was coming next，they might have had second thoughts. 解析：考查虚拟语气中的情态动词。本句是一个倒装句，可还原为：if they had known what was coming next，they...second thought。根据had known提示，可知是与过去事实相反，因此虚拟语气主句中应该用would/might＋have done。
?Jack described his father，who must have been a brave boy many years ago，as a strong－willed man. 解析：考查情态动词推测用法。 句意为 “杰克把他的父亲描述为一个意志坚强的人， 他的父亲多年前肯定是一个勇敢的男孩子”。用must have been表示对过去事情的肯定推测。 ?—Sorry，Professor Smith.I didn't finish the assignment yesterday. —Oh，you should have done it as yesterday was the deadline. 解析：根据句意，此处表示和过去事实相反的情况，应该用 should＋have done，表示“本来应该做而未做”。 3、表示能力、许可的情态动词的用法。 （1）表示能力: can, could, be able to
be able to 能用于各种时态。can / could 只能表示现在或过去的能力。
was / were able to : “设法做成某事”相当于managed to do sth. / succeeded in doing sth.。 （2）表示许可: may / might, can / could
might, could 比较委婉, 一般多用于疑问句，can, may 表达的语言比较随便. 在以could, might 表示征询对方意见或表示请求时，回答应相应使用can, may.
有些结构只能用于肯定句，有的只能用于否定句，有的既可以用于肯定句，又可以用于否定句。
ought to的用法
1、ought to是情态动词，只有一种形式，后边接动词不定式，to不能省略。ought to没有人称和数的变化，后接动词原形可以表示现在、将来或过去将来，由时间状语或上下文决定。 They ought to come tomorrow.
He thought that they ought to take part in the design.
2、ought的否定形式由直接加not构成，疑问式将ought提到句首构成。 He ought not to do it. = He oughtn’t to do it. Ought we to do it at once?
3、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。 I feel that we ought to accept his proposal. 我觉得我们应该接受他的建议。 4、ought to还可表示可能性。 It ought to be a close game.
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山西省灵丘县第四中学 人教新课标高一英语下学期必修3第2单元
那很可能是场势均力敌的比赛。
提示：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“准是”(但语气比must要弱)。
have to的用法
have to“不得不”，有时态、人称和数的变化，其否定形式和疑问形式需要借助助动词do。 I have to leave her alone.(肯定句) 我不得不留她一个人。
You don't have to be alone.(否定句) 你不需要被孤立一人。
When do you have to be at home？(疑问句) 什么时候你该在家？
He had to be there at once.(过去式) 他得立刻赶到那儿。 提示：
1、have to的否定式为don't have to，表示“没有义务或没有必要做某事”，意为“不必”，常可以回答must提问的一般疑问句。而must的否定式mustn't表示“禁止”。 — Must I hand in the paper tomorrow? —我明天必须交讲义吗？
— No, you needn't/don't have to. (Yes, you must.) —不，没必要。(是的，必须。)
2、have to侧重客观需要，有时态、人称和数的变化。 must指说话人的主观看法，无时态、人称和数的变化。 ?I have to go now, for my mother is ill. 现在我不得不走了，因为我妈妈生病了。 ?I must stop smoking．我一定要戒烟。
need的用法
1、need作情态动词时，后跟动词原形，表示“需要，有必要”，无人称和数的变化，多用于否定句、疑问句或条件句中。
I wonder if we need take sleeping bags. 我不知道我们是否需要带睡袋。 You needn't complete the essay tonight. 你不必今晚就完成这篇文章。 Need they have done it yesterday?
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山西省灵丘县第四中学 人教新课标高一英语下学期必修3第2单元
他们昨天做这件事有必要吗？ 提示：
1、由need引导的一般疑问句的肯定回答常用must或have to，否定回答常用needn't。 — Need I stay to help them? —我必须留下来帮他们吗？ — Yes, you must. (No, you needn't.) —是，你必须。(不，你不必。)
2、作为实义动词，同其他实义动词一样，可用于各种句式，有时态、 人称、数的变化，构成否定句和疑问句时要借助于助动词do或does。
The machine needs to be repaired.＝The machine needs repairing. 这台机器需要修理。
情态动词专项训练
一、用所学情态动词完成句子
1．I ________________ (不得不参加) an important meeting this afternoon. 2．You ________________ (一定不能玩) with fire, or you'll get burnt.
3．Something is wrong with my bike. So my bike ________________ (需要修理)． 4．You _________ (不必归还) the book now. You can keep it until next week if you like. 5．You ________________ (本不必告诉) him the news; I had told him.
6．Mary _________ (本不该说) the words, but she wanted to warn you against that man. 7．The light is on in his office. He ________________ (一定在工作) there now. 8．In some parts of the world, you ________ boil the water before drinking it.
9．I didn't see her in the meeting room this morning. She_____ have missed the meeting. 10．You ________ run, for we have enough time to catch the train.
11．— ________________ I water the trees on Tuesday? — No, you needn't. 12．We ________________ (receive) the letter yesterday, but it didn't arrive.
13．When we got to the cinema, the film hasn't started yet, so we ___________ (hurry)． 二、用方框内所给情态动词填空
will would can could must should ought to may might need Thank you for your letter. I don't think I 1.________ give you any advice. I don't think the manager 2.________ trust you. It sounds as if he has decided that you 3.________ be the thief. Do you have to continue working at this company? Maybe you 4.________ find another job where the people are friendly. I think you 5.________ enjoy that more.
If you stay at the meat factory, you 6.________ not be able to be happy. Besides, if you stay, the thief 7._______ do something bad to you. I don't think that 8.________ be very pleasant. If he played a trick on you, the manager 9.________ say you were the thief and call in the police. That 10.________ have serious results. I think
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人教版高中英语2019-2020学年高一年级下学期必修3 uint 2 Healthy eating 语法之情态动词（含答案）
