if引導(dǎo)的虛擬語(yǔ)氣（課堂PPT）

1、1真實(shí)條件句和真實(shí)條件句和虛擬條件句虛擬條件句231.表示客觀事實(shí)或真理表示客觀事實(shí)或真理 If you freeze water, it turns to ice. If you eat a lot of chocolate, you put on weight. 真實(shí)條件句真實(shí)條件句 從句從句 主句主句 if+一般現(xiàn)在時(shí)，一般現(xiàn)在時(shí)一般現(xiàn)在時(shí)，一般現(xiàn)在時(shí)42.表示將來(lái)可能發(fā)生的事表示將來(lái)可能發(fā)生的事 If he fails in the exam, he will let his parents down. You will certainly succeed if you keep on

2、 trying. 從句從句 主句（陳述句）主句（陳述句） if+一般現(xiàn)在時(shí)，一般將來(lái)時(shí)（一般現(xiàn)在時(shí)，一般將來(lái)時(shí)（will+動(dòng)詞原形）動(dòng)詞原形）53.給某人提建議或命令某人做某事給某人提建議或命令某人做某事 If you feel sleepy, go to bed. If you want to know how it works, read the instructions. 從句從句 主句主句if+一般現(xiàn)在時(shí)，祈使句一般現(xiàn)在時(shí)，祈使句6If引導(dǎo)的虛擬條件句，即非真實(shí)條件引導(dǎo)的虛擬條件句，即非真實(shí)條件句，表示條件句所表示的條件根本句，表示條件句所表示的條件根本不可能實(shí)現(xiàn)或?qū)崿F(xiàn)的可能性很小。不

3、可能實(shí)現(xiàn)或?qū)崿F(xiàn)的可能性很小。根據(jù)動(dòng)作發(fā)生時(shí)間的不同，含有非根據(jù)動(dòng)作發(fā)生時(shí)間的不同，含有非真實(shí)條件句的復(fù)合句的主從句的謂真實(shí)條件句的復(fù)合句的主從句的謂語(yǔ)動(dòng)詞采用不同的表達(dá)方式。具體語(yǔ)動(dòng)詞采用不同的表達(dá)方式。具體分為三種情況：分為三種情況：虛擬條件句虛擬條件句7時(shí)間時(shí)間從句從句主句主句與與現(xiàn)在現(xiàn)在事實(shí)相反事實(shí)相反過(guò)去式過(guò)去式（be 通常用通常用were） should would could +動(dòng)詞原形動(dòng)詞原形 might與與過(guò)去過(guò)去事實(shí)相反事實(shí)相反 had+過(guò)去分詞過(guò)去分詞 should would could +have+過(guò)去分詞過(guò)去分詞 might與與將來(lái)將來(lái)事實(shí)相反事實(shí)相反過(guò)去式（過(guò)去式（

4、be 通常通常用用were）should+動(dòng)詞原形動(dòng)詞原形were to+動(dòng)詞原形動(dòng)詞原形 should would could +動(dòng)詞原形動(dòng)詞原形 might8一、與現(xiàn)在現(xiàn)在事實(shí)相反If I knew his telephone number, I would tell you .If I were you ,I wouldnt be so proud.9 二、與過(guò)去過(guò)去事實(shí)相反1.If he had taken my advice, he would not have made such a mistake.2.If I had got there earlier, I would hav

5、e met her.10 三、與將來(lái)將來(lái)的事實(shí)相反1.If there were a heavy snow next Sunday, we would not go skating.2.If she should come, I would tell her about the matter.11The printer is of good quality. If it _break down within the first year , we would repair it at our expense.A. would B. shouldC. couldD. might122._,the

6、 forest fire would have been discovered much earlier.A. But for their careB. If they were careful C. Without their careD. If they had been more careful134.The weather has been very hot and dry.Yes. If it had rained even a drop, things would be much better now! And my vegetables_.A. wouldnt dieB. didnt dieC. hadnt diedD. wouldnt have died145.Had I known about the computer program, a huge amount of time and energy_.A. would have been savedB. had been savedC. will be savedD. was saved156.If we _ the ot