情態(tài)動(dòng)詞表虛擬和推測-已整理

1、情態(tài)動(dòng)詞+ have done動(dòng)詞 + 動(dòng)詞完成式即“情態(tài)動(dòng)詞 + have + done”，表示對(duì)過去行為或動(dòng)作進(jìn)行推測、評(píng)論或判斷。這個(gè)結(jié)構(gòu)是近幾年高考情態(tài)動(dòng)詞的重點(diǎn)和難點(diǎn)。一、在虛擬語氣中的用法1. should have done 表示“過去本應(yīng)該做某事卻未做?！逼浞穸ńY(jié)構(gòu)shouldn't have done 表示 “過去本不該做某事卻做了?！?. ought to have done 表示“過去本應(yīng)該做某事卻未做。 ”其否定結(jié)構(gòu) oughtn't to have done 表示 “過去本不該做某事卻做了。”3. need have done 表示“過去本有必要做某事

2、卻未做?！?其否定結(jié)構(gòu) needn't have done 表示“過去本沒必要做某事卻做了?！?. could ( 不能用can) have done 表示“過去本能夠做某事卻未做?！弊⒁猓浩浞穸ㄐ问絚ouldn'thave done 沒有虛擬語氣的用法，couldn't have done只能表推測，相當(dāng)于can't have done ，意為：“過去不可能做了某事?！?. might (不能用 may) have done 表示“過去本可以做某事卻未做。”注意：其否定形式might not have done 沒有虛擬語氣的用法， might not hav

3、e done 只能表推測， 相當(dāng)于 may not have done，意為：“過去可能沒有做某事。”二、表推測的用法1. must have done表示對(duì)過去某事的肯定猜測，譯為：過去肯定做了某事。不存在mustn't have done 的形式。其否定或疑問形式須用can(could) 來表示 . 例如：Since the road is wet, it must have rained last night.既然路是濕的，那昨天晚上肯定下雨了。He can't have missed the way. I drew him a map.他不可能迷路。我（當(dāng)時(shí)）給他畫了張

4、圖。“The dictionary has disappeared. Who could have taken it? ” 詞典不見了，（過去）誰可能把它拿走了？2. may / might have donemay / might have done 表示“過去可能做了某事”。 may 比 might 表示的可能性在說話人看來稍大些。 may/might not have done 表示“過去可能沒有做某事?！崩纾篒 can't find my keys. I may / might have left them at the school yesterday.我找不到我的鑰匙了。

5、精選文庫我可能昨天把他們落在學(xué)校了。John may/might not have passed the exam; he looks very sad. 約翰可能沒有通過考試。 他看起來很憂傷。注意： may/might have done 表推測不能用于疑問句中。3. can/could have done 表推測一般用在否定句和疑問句中，表示不相信或懷疑的態(tài)度。Can/Could he have passed the exam?他可能通過了考試嗎？I think that he couldn t/can't have gone abroad. I saw him just now

6、. 我認(rèn)為他不可能出國了。我剛才還看見他了。注：表示推測過去某動(dòng)作發(fā)生的可能性時(shí)，就表示的可能性程度而言，must 最大， could 其次， may 更次之， might 最小。例如：“I wonder how Tom knew about your past. ” “我想知道湯姆是怎么知道你的過去的?！薄癏e must / could / may / might have heard of it from Mary. ” “他肯定 /很可能 /可能 /興許（沒準(zhǔn)兒）已從瑪麗那兒聽說此事了?！比?、高考例析1. Sorry I'm late. I _ have turned off t

7、he alarm clock and gone back to sleep again.（2000北京春季）A. mightB. shouldC. canD. will答案為 A 。表推測的用法。句意：對(duì)不起，我遲到了。我（當(dāng)時(shí)）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. n

8、eedn't leave答案為 B 。虛擬語氣用法。句意：我（那時(shí)）真地很擔(dān)心你。你本不應(yīng)該不留個(gè)話就離開家。3. I ll 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-2精選文庫答案為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,

9、 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(shí)候就大學(xué)畢業(yè)了。哦，他肯定是一個(gè)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：

10、他肯定做完了工作，不然他就不會(huì)在海邊痛快地玩兒了。6. Do you know where David is? I couldn't find him anywhere. Well. He have gone far his coat's still here. （ 05 湖北卷）A shouldn't B mustn't C can't D wouldn'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。四、練習(xí)1.

11、 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 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）A. mus

12、t drop B. must have dropped-3精選文庫C. must be dropping D. must have been dropped3. Mr. White _ at 8:30 for the meeting, but he didn't show up.（ 04 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）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 happened6.I _ have been more than six years old when the accident happened. （ 05天津卷