1、六虛擬語(yǔ)氣 語(yǔ)氣：用動(dòng)詞形式的變化來(lái)表示說(shuō)話(huà)的人對(duì)自己說(shuō)的話(huà)所持的看法和態(tài)度，叫做語(yǔ)氣. 語(yǔ)氣分為三種： 陳述語(yǔ)氣：陳述事實(shí)，如: You are very careful. 祈使語(yǔ)氣：提出請(qǐng)求，命令等，如： Please be careful. Be quielt. 虛擬：表示說(shuō)話(huà)人認(rèn)為自己所說(shuō)的話(huà)不過(guò)是一種主觀愿望或設(shè)想，或與事實(shí)相反，或不能實(shí)現(xiàn)，或?qū)崿F(xiàn)可能性不大。虛擬語(yǔ)氣有其特有的一套動(dòng)詞形式. I wish I were in Beijing now. 我現(xiàn)在要在北京就好了.（與事實(shí)相反的愿望） If air were a good conductor of heat,we shoul

2、d be burned. 若空氣是熱的良導(dǎo)體，我們就會(huì)被燒死。,虛擬語(yǔ)氣在虛擬條件句中的應(yīng)用. 條件從句有兩種，其一是真實(shí)條件句，即說(shuō)話(huà)人認(rèn)為假設(shè)的條件是真實(shí)的或完全可能發(fā)生的，其謂語(yǔ)動(dòng)詞用陳述語(yǔ)氣，如： If air is passed through a drying agent the moisture will be removed. 若使空氣通過(guò)干燥劑，其水分就會(huì)被除去。 若說(shuō)話(huà)人認(rèn)為自己假設(shè)的條件不符合事實(shí)或?qū)?lái)實(shí)現(xiàn)的可能性很小，因而相應(yīng)的推測(cè)或結(jié)果也是不真實(shí)的，這種從句就叫虛擬條件句，就得用虛擬語(yǔ)氣.這有三種基本情況： 假定的條件與現(xiàn)在的事實(shí)相反，則條件句中謂語(yǔ)動(dòng)詞用過(guò)去時(shí)（be

3、全用were）,主句中謂語(yǔ)動(dòng)詞用should,would,could,+動(dòng)詞原形. If he had time,he would help you. If I knew English,I should be able to read these English books. If there were no gravity,there would be no air around the earth. What would take place if there were no friction in the brakes of a tractor?,.假定的條件與過(guò)去事實(shí)相反，則條件句中

4、謂語(yǔ)動(dòng)詞用過(guò)去完成時(shí)，主句中謂語(yǔ)動(dòng)詞用should,would,could,+現(xiàn)在完成時(shí). If the friction had not been great,the pump would not have been damaged. If you had come here yesterday,you would have seen him. If we had known the basic principles,we should have controlled the process even better.,.與將來(lái)事實(shí)可能相反（不可能實(shí)現(xiàn)或可能性較?。┑募僭O(shè)，則條件句中謂語(yǔ)動(dòng)詞用

5、should,could,，might ,were to +動(dòng)詞原形，主句則為should,would,could+動(dòng)詞原形. If all the ice in the North Pole were to melt,the sea level all over the world would go up many meters higher. If she should come to us,she would answer these questions. (假如她真能來(lái)我們這里的話(huà)，她會(huì)回答這些問(wèn)題的).事實(shí)上她來(lái)的可能性較小，或者不存在. 現(xiàn)將以上三種情形列表示之：,2.主謂倒裝的形

6、式表示虛擬條件：若條件從句中謂語(yǔ)有were,had,should時(shí)，則省去if,把它們提前，形成倒裝： Were there no no gravity,there would be no air around the earth.= If there were no gravity,there would be no air around the earth. Were she in Tientsin,she would help us.= If she were in Tientsin,she would help us. Should they come to us,I should a

7、sk them some questions.= If they should come to us,I should ask them some questions. Had the checking up of the experimental data not taken so much time,we should have completed our work long ago.= If the checking up of the experimental data had not taken so much time,we should have completed our wo

8、rk long ago. Had there been no electronic computers,there would not have been artificial satellites or rockets.=If there had been no electronic computers,there would not have been artificial satellites or rockets.,虛擬語(yǔ)氣有兩個(gè)明顯特點(diǎn)：1）自成一體，不符合有關(guān)人稱(chēng)、數(shù)和時(shí)態(tài)的一般語(yǔ)法規(guī)則（如所有人稱(chēng)單、復(fù)數(shù)都用were,用動(dòng)詞過(guò)去時(shí)表示與現(xiàn)在相反的假設(shè)等）；2）should,wou

9、ld 用得較多。因此，判斷是否是虛擬語(yǔ)氣，通常可以從主從句時(shí)態(tài)的呼應(yīng)、上下文的時(shí)態(tài)，以及這幾種時(shí)態(tài)本身的用法，并結(jié)合句子內(nèi)容來(lái)加以考慮，如： People might have avoided many accidents if ultrasonic methods had been known before. (假如人們以前就知道超聲方法的話(huà)，許多事故或許就不會(huì)發(fā)生了) 這里的“had been known”既可以是陳述語(yǔ)氣的過(guò)去完成時(shí)，也可能是表示與過(guò)去事實(shí)相反假設(shè)的虛擬語(yǔ)氣，但主句謂語(yǔ)為“might have avoided”，正好與所作的假設(shè)和過(guò)去事實(shí)相反時(shí)，相應(yīng)的主句謂語(yǔ)的虛擬語(yǔ)氣形

10、式的規(guī)則相符。因此可以肯定，had been known 是虛擬語(yǔ)氣，而不是陳述語(yǔ)氣的過(guò)去完成時(shí)。又如： Being on the moon would be very difficult because there is no oxygen or water. In fact there is no atmosphere of any kind. (在月球上想必是非常困難的，因?yàn)槟抢餂](méi)有氧氣，沒(méi)有水，而且事實(shí)上沒(méi)有任何種類(lèi)的大氣),這里的“would be”既可以是虛擬語(yǔ)氣，也可能是過(guò)去將來(lái)時(shí)，這里并沒(méi)有表示假設(shè)的條件從句。但because 引導(dǎo)的原因狀語(yǔ)從句的謂語(yǔ)is ，以及后面一個(gè)句子的

11、謂語(yǔ)is,都是一般現(xiàn)在時(shí)，不可能表示某一特定時(shí)刻，這就使would be 失去了作過(guò)去將來(lái)時(shí)的依據(jù)，因此，依上下文時(shí)態(tài)判斷，would be 是虛擬語(yǔ)氣。,Exercise 一、單項(xiàng)填空，在A、B、C、D四個(gè)答案中，選出可以填入空白處的正確答案。 1.If I-you ,I wouldnt return the call. a. be b. am c. was d. were 2. I would have gone to ,the meeting ,if I-time. a. had had b. have had c. had d. wold have had 3. If you had

12、been with us, you-our excitement. a. have understood b. understood c. will understand d. would have understood 4.-today, he would get there by Friday. a. Would he leave b. Was he leaving c. Were he to leave d. If he leaves 5. I didnt know this Picasso exhibit was closed, but I wouldnt have been to c

13、ome even if -about it. a. I know b. Id known c. I have been knowing d. Ive known,6. If I had time,-see that new movies at the University Theater. a. Ill be b. I shall c. I may d. Id 7. Without your help, we- so much. a. will not achieve b. didnt achieve c. dont achieve d. would not have achieved 8. -,Id have told you. a. If I would have known it, b. If I