情態(tài)動詞完成時的推測

1、 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 you so much. Its beautiful. But you neednt have bought it. She

2、 has so many at home.Finding the ruleModal verbs + have doneExplanationsExample sentencesmust have doneIt must have rained last night.Believing what happened in the past is the case (used only in positive sentences)can/could have done -Where is John? Can he have gone to the playground?-No, he cant h

3、ave gone to the playground. It is raining.indicating that something was a possibility in the past , though it did not actually happen (negative or interrogative sentences)may/might have doneThey might have mistaken you.Suggesting that it is possible that something happened or was true (used only in

4、positive/ negative sentences)should/shouldnt have doneYou should have done your homework first.indicating that something did not / did happen, but the speaker wishes it had (not) happened.neednt have doneYou neednt have watered the plant. It rained last night.indicating that it is not necessary for

5、sb. to do sth, though he / she did it. 對已發(fā)生的過去情況的推測，若陳述對已發(fā)生的過去情況的推測，若陳述句謂語部分有句謂語部分有“must have done”，而，而且且有表示過去的時間狀語有表示過去的時間狀語, 問句部分問句部分用用didnt； 1) They must have gone there last night, didnt they? 2)They must have arrived by now, havent they?對已發(fā)生的過去情況的推測，若陳述對已發(fā)生的過去情況的推測，若陳述句謂語部分有句謂語部分有“must have don

6、e”，若，若沒有表示過去的時間狀語，問句部分沒有表示過去的時間狀語，問句部分用用havent 或或hasnt .3) He must have been to the Great Wall,hasnt he? 對已發(fā)生的過去情況的推測，若陳述對已發(fā)生的過去情況的推測，若陳述句謂語部分有句謂語部分有“must have done”，若，若沒有表示過去的時間狀語沒有表示過去的時間狀語，問句部分，問句部分用用havent 或或hasnt .這個房間昨天肯定被清掃了。這個房間昨天肯定被清掃了。The room _ _ _ _ yesterday. must have been cleaned他一定已經(jīng)

7、背了他一定已經(jīng)背了5000單詞了。單詞了。He _ _ _ 5,000 words.must have learntYou must have seen the film “Journey to the West” , _ _? havent youThey must have been to the World Expo last week, _ _? didnt they-Where is John? Can he have gone to the playground?-No, he cant have gone to the playground It is raining.- _Mr

8、 King _the letter?金先生已經(jīng)收到那封信了嗎？金先生已經(jīng)收到那封信了嗎？-No, he _it.不，他不可能收到。不，他不可能收到。Canhave receivedcant have receivedmay/might have done某事有可能發(fā)生過某事有可能發(fā)生過(表示對過去的不太肯定的推測，表示對過去的不太肯定的推測，語氣比語氣比must have done 弱弱)-Where did Adam get that new football? He hasnt got any money. -It _ a present. After all, it was his bi

9、rthday last week. A. might have been B. might be He _out because the light was on.A. may not have gone B. may have not goneC. may not go D. must not have goneWe _the plant because it rained last night. (本無必要本無必要)neednt have wateredshouldnt have done本不該做某事本不該做某事（但此事已做）（但此事已做）He should have repaired t

10、he bike yesterday.should have done本應(yīng)該做某事本應(yīng)該做某事（但此事未做）（但此事未做）Oh, Im not feeling well in the stomach. I shouldnt have eaten so much fried chicken just now. 你本應(yīng)該先完成你的作業(yè)。你本應(yīng)該先完成你的作業(yè)。You _ _ _ your homework first. should have finished你本不應(yīng)該跟我撒謊。你本不應(yīng)該跟我撒謊。You _ _ _to me.shouldnt have lied高考例析高考例析 1. Sorry

11、Im late. I _ have turned off the alarm clock and gone back to sleep again. （2000 北京春季）北京春季）A. might B. should C. can D. will 答案為答案為 A。表推測的用法。句意：對。表推測的用法。句意：對不起不起, 我遲到了。我我遲到了。我(當(dāng)時當(dāng)時)興許是關(guān)興許是關(guān)了鬧鐘又回去睡覺了。了鬧鐘又回去睡覺了。might 相當(dāng)于相當(dāng)于 may, 但語氣更加不肯定。但語氣更加不肯定。2. I was really anxious about you. You_ home without a

12、word. (01 全國全國)A. mustnt leave B. shouldnt have left C. couldnt have left D. neednt leave 答案為答案為 B。虛擬語氣用法。句意：我。虛擬語氣用法。句意：我（那時）真地很擔(dān)心你。你本不應(yīng)該（那時）真地很擔(dān)心你。你本不應(yīng)該不留個話就離開家。不留個話就離開家。3. Ill tell Mary about her new job tomorrow. You_ her last week. （04 福建）福建）A. ought to tell B. would have told C. must tell D. s

13、hould have told答案為答案為 D。虛擬語氣用法。句意：。虛擬語氣用法。句意：-我明天要告訴她我的新工作的情我明天要告訴她我的新工作的情況。況。 -你本應(yīng)該上周告訴她。你本應(yīng)該上周告訴她。4. Tom graduated from college at a very young age. Oh, he _ have been a very smart boy then. （04 全國全國IV） A. could B. should C. might D. must答案為答案為 D。表推測的用法。句意：。表推測的用法。句意：湯姆很年輕的時候就大學(xué)畢業(yè)了。湯姆很年輕的時候就大學(xué)畢業(yè)了。

14、哦，他肯定是一個很聰明的男孩兒。哦，他肯定是一個很聰明的男孩兒。 5. He _ have completed his work; otherwise, he wouldnt be enjoying himself by the seaside. (05 北京卷北京卷) A. should B. must C. wouldnt D. cant答案為答案為 B。用法同。用法同4題。句意：他題。句意：他肯定做完了工作，不然他就不會肯定做完了工作，不然他就不會在海邊痛快地玩兒了。在海邊痛快地玩兒了。 6. Do you know where David is? I couldnt find him

15、anywhere. Well. He _ have gone farhis coats still here. （05湖北卷）湖北卷） Ashouldnt Bmustnt Ccant Dwouldnt答案為答案為 C。表推測的用法。句意：。表推測的用法。句意：你你知道大衛(wèi)在哪兒嗎？我哪兒也找不到知道大衛(wèi)在哪兒嗎？我哪兒也找不到他。他。瞧，他不可能走遠(yuǎn)瞧，他不可能走遠(yuǎn)他的上衣還他的上衣還在這兒呢。在這兒呢。cant 相當(dāng)與相當(dāng)與 couldnt，但，但后者語氣更加委婉。后者語氣更加委婉。 練習(xí)練習(xí)1. The woman biologist stayed in Africa studying w

16、ild animals for 13 years before she returned. Oh, dear! She _ a lot of difficulties! (05 江蘇卷江蘇卷) A. may go through B. might go throughC. 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）北京春季）A. must drop B. must have dropped C. must be d

17、ropping D. must have been dropped 3. Mr. White _ at 8:30 for the meeting, but he didnt show up. （04 廣西）廣西） 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 山東卷）山東卷）A. could B. would C. must D. need5. Tom is never late fo