情态动词完成时的推测.ppt

1、,Why is the road so wet?,It must have rained last night.,A: Where are the girls? Can they have gone home? B: No, they cant have gone home. Its so early.,-Look, the lights are off in their room. -Where have they gone? -They might have gone to the cinema.,A: Here is a doll for your daughter. B: Thank

2、you so much. Its beautiful. But you neednt have bought it. She has so many at home.,Finding the rule,Believing what happened in the past is the case (used only in positive sentences),indicating that something was a possibility in the past , though it did not actually happen (negative or interrogativ

3、e sentences),Suggesting that it is possible that something happened or was true (used only in positive/ negative sentences),indicating that something did not / did happen, but the speaker wishes it had (not) happened.,indicating that it is not necessary for sb. to do sth, though he / she did it.,mus

4、t have done 对过去的非常肯定的 推测 （语气最强）,对已发生的过去情况的推测，若陈述句谓语部分有“must have done”，而且有表示过去的时间状语, 问句部分用didnt；,1) They must have gone there last night, didnt they?,2)They must have arrived by now, havent they?,对已发生的过去情况的推测，若陈述句谓语部分有“must have done”，若没有表示过去的时间状语，问句部分用havent 或hasnt .,3) He must have been to the Gre

5、at Wall, hasnt he?,对已发生的过去情况的推测，若陈述句谓语部分有“must have done”，若没有表示过去的时间状语，问句部分用havent 或hasnt .,这个房间昨天肯定被清扫了。 The room _ _ _ _ yesterday.,must have been cleaned,他一定已经背了5000单词了。 He _ _ _ 5,000 words.,must have learnt,You must have seen the film “Journey to the West” , _ _?,havent you,They must have been

6、to the World Expo last week, _ _?,didnt they,can have done 对过去的疑问推测,cant have done 对过去的否定推测,疑问句 和 否定句,-Where is John? Can he have gone to the playground? -No, he cant have gone to the playground It is raining.,- _Mr King _the letter? 金先生已经收到那封信了吗？ -No, he _it. 不，他不可能收到。,Can,have received,cant have r

7、eceived,may/might have done 某事有可能发生过 (表示对过去的不太肯定的推测， 语气比must have done 弱),用于肯定句 和否定句 (may的语气 比might稍强),-Where did Adam get that new football? He hasnt got any money. -It _ a present. After all, it was his birthday last week. A. might have been B. might be,He _out because the light was on. A. may not

8、 have gone B. may have not gone C. may not go D. must not have gone,neednt have done 本没有必要做某事 （但此事已做）,We _the plant because it rained last night. (本无必要),neednt have watered,shouldnt have done 本不该做某事 （但此事已做）,表示责备,He should have repaired the bike yesterday.,should have done 本应该做某事 （但此事未做）,表示责备,Oh, Imn

9、otfeelingwellinthestomach. Ishouldnt have eaten so much fried chicken just now.,你本应该先完成你的作业。 You _ _ _ your homework first.,should have finished,你本不应该跟我撒谎。 You _ _ _to me.,shouldnt have lied,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. might

10、B. should C. can D. 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 leaveB. 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. Ill tell Mary abo

11、ut her new job tomorrow. You_ her last week. （04 福建）A. ought to tell B. would 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.

12、 must,答案为 D。表推测的用法。句意：汤姆很年轻的时候就大学毕业了。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 himself by 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。,6. Do you know where David is? I couldnt find him anywhere. Well. He

13、 _ have gone farhis coats still here. （05湖北卷） Ashouldnt Bmustnt Ccant Dwouldnt,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。,练习, The woman biologist stayed in Africa studying wild animals for 13 years before she returned. Oh, dear! She _ a lot of difficulties! (05

14、江苏卷) A. may go through B. might go throughC. ought to have gone through D. must have gone through,2. 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,3. Mr. White _ at 8:30 for the meeting, but he didnt show up. （04 广西） A. should have arrived B. should 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. need,5. Tom is never late for work. Why is he absent today?