,Why is the road so wet?,It must have rained last night.,must have done 對過去的非?？隙ǖ?推測 （語氣最強(qiáng)）,對已發(fā)生的過去情況的推測，若陳述句謂語部分有“must have done”，而且有表示過去的時間狀語, 問句部分用didn't；,1) They must have gone there last night, didn't they?,2)They must have arrived by now, havent they?,對已發(fā)生的過去情況的推測，若陳述句謂語部分有“must have done”，若沒有表示過去的時間狀語，問句部分用havent 或hasnt .,3) He must have been to the Great Wall, hasn't he?,對已發(fā)生的過去情況的推測，若陳述句謂語部分有“must have done”，若沒有表示過去的時間狀語，問句部分用havent 或hasnt .,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)背了5000單詞了。 He _ _ _ 5,000 words.,must have learnt,You must have seen the film “Journey to the West” , _ _?,havent you,They must have been to the World Expo last week, _ _?,didnt they,A: Where are the girls? Could they have gone home? B: No, they cant have gone home. Its so early.,can have done 對過去的疑問推測,cant have done 對過去的否定推測,疑問句 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? 金先生已經(jīng)收到那封信了嗎？ -No, he _it. 不，他不可能收到。,Can,have received,cant have received,-Look, the lights are off in their room. -Where have they gone? -They might have gone to the cinema.,may/might have done 某事有可能發(fā)生過 (表示對過去的不太肯定的推測， 語氣比must have done 弱),用于肯定句 和否定句 (may的語氣 比might稍強(qiáng)),-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 have gone B. may have not gone C. may not go D. must not have gone,A: Here is a doll for your daughter. B: Thank you so much. Its beautiful. But you neednt have bought it. You have bought so many for her .,neednt have done 本沒有必要做某事 （但此事已做）,We _the plant because it rained last night. (本無必要),neednt have watered,Oh,I'm not feeling well in the stomach. I shouldnt have eaten so much fried chicken just now.,shouldnt have done 本不該做某事 （但此事已做）,表示責(zé)備,He should have repaired the bike yesterday.,should have done 本應(yīng)該做某事 （但此事未做）,表示責(zé)備,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。 You _ _ _to me.,shouldnt have lied,could + have done “本能夠，本可以做某事” 但卻沒做 他本能夠按時完成這項任務(wù)的。 He _the task on time, but he didnt do it.,could have finished,Finding the rule,Believing what happened in the past is the case (used only in positive sentences),It must have rained last night.,indicating that something was a possibility in the past , though it did not actually happen (negative or interrogative sentences),Suggesting that it is possible that something happened or was true (used only in positive/ negative sentences),They might have mistaken you,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.,You neednt have watered the plant. It rained last night.,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 B. should C. can D. will,答案為 A。表推測的用法。句意：對不起, 我遲到了。我(當(dāng)時)興許是關(guān)了鬧鐘又回去睡覺了。might 相當(dāng)于 may, 但語氣更加不肯定。,2. I was really anxious about you. You_ home without a word. (01 全國) A. mustn't leave B. shouldn't have left C. couldn't have left D. needn't leave,答案為 B。虛擬語氣用法。句意：我（那時）真地很擔(dān)心你。你本不應(yīng)該不留個話就離開家。,3. Ill tell Mary about 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,答案為 D。虛擬語氣用法。句意：-我明天要告訴她我的新工作的情況。 -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IV） A. could B. should C. might D. must,答案為 D。表推測的用法。句意：湯姆很年輕的時候就大學(xué)畢業(yè)了。哦，他肯定是一個很聰明的男孩兒。,5. He _ have completed his work; otherwise, he wouldn't be enjoying himself by the seaside. (05 北京卷) A. should B. must C. wouldn't D. can't,答案為 B。用法同4題。句意：他肯定做完了工作，不然他就不會在海邊痛快地玩兒了。,6. Do you know where David is? I couldnt find him anywhere. Well. He _ have gone farhis coats still here. （05湖北卷） Ashouldn't Bmustn't Ccan't Dwouldn't,答案為 C。表推測的用法。句意：你知道大衛(wèi)在哪兒嗎？我哪兒也找不到他。瞧，他不可能走遠(yuǎn)他的上衣還在這兒呢。can't 相當(dāng)與 couldn't，但后者語氣更加委婉。,練習(xí), The woman biologist stayed in Africa studying wild animals for 13 years before she returned. Oh, dear! She _ a lot of difficulties! (05 江蘇卷) A. may go through B. might go through C. 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 didn't show up. （04 廣西） A. should have arrived B. should arrive C. should have had arrived D. should be arriving 4. He paid for a seat, when he _ have entered free. （05 山東卷） A. could B. would C. must D. need,5. Tom is never late for work. Why is he absent today? Something _ to him. (05 江西卷) A. must happen B. should have happened C. could have happened D. must have happened 6. 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,Choose the best answer for each blank.,1) I told him the news just now. Really? You _ him. He knew it already. A. shouldnt have told B. may have told C. neednt have told D. couldnt have told 2) I cant find my pen anywhere. I _ it. Thats impossible. I saw you writing with it ten minutes ago. A. might lose B. would have lost C. should have lost D. must have lost,C,D,3) That must be Jack. It cant be him. He _ within such a short time. He said he would call me as soon as he arrived. mustnt have arrived B. shouldnt have arrived C. cant have arrived D. need not have arrived 4) Where are Joan and Mary? I think they _ early. A. should have left B. must have left C. can have left D. neednt have left,C,B,5) Did you see that car nearly hit me? I _ killed. Yes. It was going so fast. Luckily you responded quickly. could have been B. may have been C. must have been D. was,B,6) Mom, I swept the floor a moment ago. Thank you, son. But you _ it. Its not very dirty yet. A. should have swept B. neednt have swept C. may have swept D. can have swept 7) Its so dry these days. Even the plant is dead. Yes. You _ it more water. A. will give B. should have given C. may send D. can have been sent,B,B,8) John passed the exam, although he didnt study very much for it. The exam _ difficult. A. cant have been B. must have been C. couldnt be D. might have been 9) I wonder why they are late. They _ the train. A. can miss B. may have missed C. could miss D. might miss,A,B,10) He _ to help us yesterday, but he didnt. You must forgive him. He was ill yesterday. should have come B. could have come C. must have come D. can have come,A,Find and correct the mistake in each of the following sentences.,She should had finished the work three days ago. 2) You are wet through. You should have been caught in the rain.,She should have finished the work three days ago.,You are wet through. You must have been caught in the rain.,.,3) I must have helped them, but I wasnt able to. 4) You mustnt have seen the movie before, for it was made last week.,I should have helped him, but I wasnt able to.,You cant have seen the movie before, for it was made last week,5) All the lights were off at eleven last night. The students mustnt have been studying in the classroom until twelve.,All the lights were off at eleven last night. The students cant have been studying in the classroom until twelve.,Fill in each blank with the present perfect form of a model verb.,1) Husband: I bought a new skirt for you. Wife: Thank you, dear. But you _ _ done that. Ive got so many. 2) Mother: Who _ cooked the meal? Daughter: It must have been Father. Mother: It cant have been your father. He told me he was going to Chengdu on business this morning.,have,could/can have,neednt,3) Policeman: You _ stopped at the red light. Why did you keep on driving? Driver: Im terribly sorry. I didnt see the light. 4) Teacher: Everyone is listening carefully. Why did you look out of the window? Student: Im sorry. I _ done that.,should have,shouldnt have,