情态动词表虚拟和推测-已整理

1、。情态动词+ have done动词+动词完成式即“情态动词+ have + done”，表示对过去行为或动作进行推测、评论或判断。这个结构是近几年高考情态动词的重点和难点。一、在虚拟语气中的用法1. shouldhavedone表示“过去本应该做某事却未做。”其否定结构shouldnthavedone表示“过去本不该做某事却做了。”2. ought to have done表示“过去本应该做某事却未做。”其否定结构oughtnt to havedone表示“过去本不该做某事却做了。”3. need have done表示“过去本有必要做某事却未做。”其否定结构neednt have done

2、表示“过去本没必要做某事却做了。”4. could ( 不能用 can) have done表示“过去本能够做某事却未做。”注意：其否定形式couldnthavedone没有虚拟语气的用法，couldnthavedone只能表推测，相当于cant have done，意为：“过去不可能做了某事。”5. might (不能用may) have done表示“过去本可以做某事却未做。”注意：其否定形式 might not have done没有虚拟语气的用法，might not have done只能表推测，相-可编辑修改 -。当于may not have done，意为：“过去可能没有做某事。”

3、二、表推测的用法1. must have done表示对过去某事的肯定猜测，译为：过去肯定做了某事。不存在mustnt have done的形式。其否定或疑问形式须用can(could)来表示 . 例如：Since the road is wet, it must have rained last night.既然路是湿的，那昨天晚上肯定下雨了。He cant have missed the way. I drew him a map.他不可能迷路。我（当时）给他画了张图。“The dictionary has disappeared. Who could have taken it?” 词典

4、不见了，（过去）谁可能把它拿走了？2. may / might have donemay / might have done表示“过去可能做了某事”。may比 might表示的可能性在说话人看来稍大些。may/might not have done表示“过去可能没有做某事。”例如：-可编辑修改 -。I cant find my keys. I may / might have left them at the school yesterday.我找不到我的钥匙了。我可能昨天把他们落在学校了。John may/might not have passed the exam; he looks ve

5、ry sad.约翰可能没有通过考试。他看起来很忧伤。注意： may/might have done表推测不能用于疑问句中。3. can/could have done表推测一般用在否定句和疑问句中，表示不相信或怀疑的态度。Can/Could he have passed the exam?他可能通过了考试吗？I think that he couldnt/cant have gone abroad. I saw him just now.我认为他不可能出国了。我刚才还看见他了。注：表示推测过去某动作发生的可能性时，就表示的可能性程度而言，must最大，could其次， may更次之， migh

6、t最小。例如：“I wonder how Tom knew about your past.”“我想知道汤姆是怎么知道你的过去的。”“He must / could / may / might have heard of it from Mary.” “他肯定 / 很可能 / 可-可编辑修改 -。能 / 兴许（没准儿）已从玛丽那儿听说此事了。”三、高考例析1. Sorry Im late. I _ have turned off the alarm clock and gone back to sleep again. （2000 北京春季）A. mightB. shouldC. canD.

7、will答案为A 。表推测的用法。句意：对不起，我迟到了。我（当时）兴许是关了闹钟又回去睡觉了。 might相当于may,但语气更加不肯定。2. I was really anxious about you. You_ home without a word.（ 01全国）A. mustnt leave B. shouldnt have left C. couldnt have left D. neednt leave答案为B。虚拟语气用法。句意：我（那时）真地很担心你。你本不应该不留个话就离开家。3. I ll tell Mary about her new job tomorrow.You

8、_ her last week.（04福建）-可编辑修改 -。A ought to tell Bwould have told C must tell D should have told答案为D 。虚拟语气用法。句意：- 我明天要告诉她我的新工作的情况。- 你本应该上周告诉她。4. Tom graduated from college at a very young age. Oh, he _ have been a very smart boy then.（ 04全国 IV ）A. could B. should C. might D. must答案为D 。表推测的用法。句意：汤姆很年轻的

9、时候就大学毕业了。哦，他肯定是一个很聪明的男孩儿。5. He _ have completed his work; otherwise, he wouldnt be enjoying himselfby the seaside. (05北京卷 )A. should B. must C. wouldnt D. cant答案为B。用法同 4 题。句意：他肯定做完了工作，不然他就不会在海边痛快地玩儿了。-可编辑修改 -。6. Do you know where David is? I couldnt find him anywhere. Well. He have gone far his coat

10、s still here.（ 05 湖北卷）A shouldnt B mustnt C cant D wouldnt答案为C。表推测的用法。句意：你知道大卫在哪儿吗？我哪儿也找不到他。瞧，他不可能走远他的上衣还在这儿呢。cant相当与couldnt，但后者语气更加委婉。四、练习1. ThewomanbiologiststayedinAfricastudyingwildanimalsfor13yearsbefore she returned.Oh, dear! She _ a lot of difficulties! (05江苏卷 )A. may go through B. might go t

11、hroughC. ought to have gone through D. must have gone through2. I have lost one of my gloves. I _ it somewhere.（ 05北京春季）-可编辑修改 -。A. must drop B. must have droppedC. must be dropping D. must have been dropped3.Mr. White _ at 8:30 for the meeting, but he didnt show up.（04广西）A. should have arrived B. s

12、hould arriveC. should have had arrived D. should be arriving4.He paid for a seat, when he _ have entered free.（05山东卷）A. could B. would C. must D. need5. Tom is never late for work. Why is he absent today? Something _ to him. (05江西卷 )A must happen B should have happenedC could have happened D must have happened-可编辑修改 -。6. I _ have been more than six years old when the accident happened.（ 05天津卷）A. shouldnt B. couldnt C. mustnt D. neednt7. This cake is