條件句中的虛擬語(yǔ)氣

　　第一節(jié)：if引導(dǎo)的條件句中的虛擬語(yǔ)氣

　　虛擬語(yǔ)氣表示一種不能實(shí)現(xiàn)的假設(shè)。該語(yǔ)法主要用于if條件狀語(yǔ)從句。

　　一、if引導(dǎo)的條件狀語(yǔ)從句的分類及虛擬條件句的判斷

　　1、可以把條件句分為兩類：

　　1).真實(shí)條件句(Sentences of Real Condition)：凡是假設(shè)的情況發(fā)生性可能很大，就是真實(shí)條件句。例如：

　�、�、If I have time , I will help you with this work.如果我有時(shí)間會(huì)幫助你做此工作的。

　　⑵、As long as I say anything wrong, you must point it out.只要我說(shuō)了什么錯(cuò)話，你一定要指出來(lái)。

　　⑶、If time permits, we'll go fishing together.(如果有時(shí)間的話，我們就一起去釣魚。)

　　2).虛擬條件句(Sentences of Unreal Condition)：當(dāng)假設(shè)是不大可能實(shí)現(xiàn)時(shí)，就是虛擬條件句。例如：

　　⑴、If I were you , I would have attended the meeting. 如果我是你的話，就去參加會(huì)議了。

　�、�、If he had come here yesterday, he would have seen his old friend.假如他昨天來(lái)這兒的話，就會(huì)看見(jiàn)他的老朋友。

　　⑴、If it had rained yesterday, we would have stayed at home.(如果昨天下雨的話，我們就會(huì)留在家里。)

　　2、.if條件狀語(yǔ)從句中虛擬語(yǔ)氣的判斷

　　判斷是真實(shí)條件句還是非真實(shí)條件句。只有在非真實(shí)條件句中才使用虛擬語(yǔ)氣。通過(guò)句子意思，看假設(shè)的條件是否能夠?qū)崿F(xiàn)，能夠?qū)崿F(xiàn)是真實(shí)條件句，不能使用虛擬語(yǔ)氣;假設(shè)的條件不能實(shí)現(xiàn)則是非真實(shí)條件句，要用虛擬語(yǔ)氣。

　　判斷這個(gè)假設(shè)是與哪個(gè)事實(shí)相反。通常有三種情況：①與過(guò)去事實(shí)相反。②與現(xiàn)在事實(shí)相反。③與將來(lái)事實(shí)可能相反。

　　3、“后退一步法”

　　后退一步法是指在準(zhǔn)確地判斷了該句與哪一事實(shí)相反后，按虛擬語(yǔ)氣的后退一步法處理從句謂語(yǔ)動(dòng)詞的時(shí)態(tài)。即：在非真實(shí)條件狀語(yǔ)從句中，謂語(yǔ)動(dòng)詞按正常情況“后退一步”。也就是：

　�、倥c過(guò)去事實(shí)相反，在從句中用過(guò)去完成時(shí)形式表示。

　�、谂c現(xiàn)在事實(shí)相反，在從句中用過(guò)去一般時(shí)形式表示。

　�、叟c將來(lái)事實(shí)可能相反，在從句中用過(guò)去將來(lái)時(shí)形式表示。

　　主句中則用情態(tài)動(dòng)詞would, should, could 等加一個(gè)與從句一致的動(dòng)詞形式。例：

　�、�、If I had come her yesterday, I would have seen him.

　�、�、If I were a teacher, I would be strict with my students.

　�、恰�If it should snow tomorrow, they couldn't go out.

　　4、注意事項(xiàng)

　�、賗f條件句中如有were, should, had，可以省去if，并使用倒裝語(yǔ)序。

　�、谠诂F(xiàn)代英語(yǔ)中if條件狀與從句中的謂語(yǔ)動(dòng)詞如果是be其過(guò)去形式一般用were。

二、虛擬語(yǔ)氣在if 引導(dǎo)的條件句中的用法：

　　(一)、表示與現(xiàn)在事實(shí)相反的情況。其句子結(jié)構(gòu)為：

　　從句：if + 主語(yǔ)+ 動(dòng)詞的過(guò)去式(be 用were) + ……

　　主句：主語(yǔ)+ would (should, could , might) + 動(dòng)詞原形+ ……

　　例：

　　1.If I were you, I would go with him.

　　2.If the weather were fine, I would go there.

　　如果天氣好，我去那兒。(事實(shí)天氣不好)

　　3.If I were you, I would read it again.

　　如果我是你的話，我再讀一遍。(事實(shí)上我不是你)

　　4.If time permitted, I would write it again.

　　如果時(shí)間允許的話，我再寫一遍。(事實(shí)上時(shí)間不允許)

　　5.If it weren’t snowing, we wouldn’t stay in the house.

　　要是現(xiàn)在不下雪的話，我們就不會(huì)待在屋里。(事實(shí)上現(xiàn)在下雪)

　　6.What would I do if I were in your place?

　　要是我處于你地位我會(huì)怎么辦?(事實(shí)上我不在你的位置上)

　　7.If he hurried, he could catch the first bus.

　　他要是快點(diǎn)能夠趕上頭班公共汽車。(可是他不著急)

　　8.If it weren’t for your help, we would get into trouble.

　　如果沒(méi)有你們的幫助，我們就會(huì)陷入困境。(而事實(shí)上得到了你們的幫助)

　　9.If we had the manpower, we could open up even more land.

　　如果有人力,我們還能開(kāi)更多的荒地.

　　10. If I were you, I would go with him.

　　(從句If I were you, 主句I would go with him.)

　　11. If I were you, I should buy it.

　　(從句用過(guò)去式動(dòng)詞were，主句用動(dòng)詞原形buy)

　　12. If I had time, I would study French.

　　(如果有時(shí)間，我會(huì)學(xué)習(xí)法文。)(從句用過(guò)去式動(dòng)詞had，主句用動(dòng)詞原形study)

　　13. If she knew English, she would not ask me for help.

　　(如果她懂英文，她就不必要我?guī)土恕?(從句用過(guò)去式動(dòng)詞knew, 主句用動(dòng)詞原形ask)

　　注意：如果動(dòng)作在進(jìn)行中，主句要用："主語(yǔ)+ would be + 進(jìn)行式動(dòng)詞+ ……"

　　14. If they were here, he would be speaking to them now.

　　(從句用過(guò)去式動(dòng)詞were, 主句用would be speaking)

　　(二)、表示與過(guò)去事實(shí)相反的虛擬條件句。其句子結(jié)構(gòu)為：

　　從句：If + 主語(yǔ)+ had +過(guò)去完成式動(dòng)詞+ ……

　　主句：主語(yǔ)+ would (should, could, might) + have +過(guò)去完成式動(dòng)詞+……

例如:

　�、�、If you had taken my advice, you would not have made such a mistake.如果你聽(tīng)了我的勸告,就不會(huì)犯這樣的錯(cuò)誤。(事實(shí)上你沒(méi)有聽(tīng)我的勸告)

　�、�、I shouldn’t have been able to write such good novels if I hadn’t lived among the peasants for five years.如果我不是和農(nóng)民生活了五年，就不可能寫出這樣好的小說(shuō)。(事實(shí)上我和農(nóng)民生活了五年)

　�、�、If you hadn’t invited me, I shouldn’t have come to the party.如果你不邀請(qǐng)我，我就不會(huì)來(lái)參加你的舞會(huì)。(事實(shí)上你邀請(qǐng)了我)

　�、�、If it hadn’t been for your help, I shouldn’t have finished this work on time. 要是沒(méi)有你們的幫忙，我就不會(huì)按時(shí)完成了這項(xiàng)工作。(事實(shí)上你們幫助了我)

　�、�、If he hadn’t broken the law, he wouldn’t have been put in prison.如果他不違法的話，就不會(huì)被打入監(jiān)獄。(事實(shí)上他違法了)

　　⑹、If I hadn’t been ill yesterday, I might have come to school.昨天要是不生病，我是可能來(lái)上學(xué)的。(事實(shí)上我生病了)

　�、�、If I had been your headmaster, I should have dismissed you from school. 我要是你們校長(zhǎng)的話，就把你開(kāi)除學(xué)籍了。(事實(shí)上我不是)

　�、獭� If you had studied harder last term, you could have passed exam.(從句動(dòng)詞用had studied, 主句動(dòng)詞用have passed)如果你在上個(gè)學(xué)期用功一些，你就會(huì)在考試中過(guò)關(guān)了。

　�、�、 If you had taken my advice, you wouldn't have failed in the exam.(從句動(dòng)詞用had taken, 主句動(dòng)詞用have failed)如果你當(dāng)時(shí)聽(tīng)從我的勸告的話，你就不會(huì)在考試中失敗了。

　　⑽、 If you had got up earlier, you could have caught the train.(從句動(dòng)詞用had got up, 主句動(dòng)詞用have caught)如果你起身得早一點(diǎn)，你就會(huì)趕得上火車了。

　�、�、 If it had snowed, I would have skied in the park.(從句動(dòng)詞用had snowed, 主句動(dòng)詞用have skied)如果下雪的話，我就可在公園里滑雪了。

　　注意：如果動(dòng)作在進(jìn)行中，主句要用："主語(yǔ)+ would + have + 完成進(jìn)行式動(dòng)詞 +……

　�、小� If they had been here, he would have been speaking to them.(從句動(dòng)詞用had been, 主句動(dòng)詞用have been speaking)

　　(三)、表示與將來(lái)事實(shí)相反的虛擬條件句(對(duì)將來(lái)的事實(shí)實(shí)現(xiàn)的可能性不大)。其句子結(jié)構(gòu)為：

　　從句：If + 主語(yǔ)+ should (或were) + 動(dòng)詞原形+……

　　主句：主語(yǔ)+ would (could, should, might) + 動(dòng)詞原形+……

　　例如：

　�、拧�If I were to work at this problem, I would do it in another way.要是我來(lái)解這道難題，我會(huì)用另外一種方法的。

　�、啤�If you were to do such a thing again, you would be punished. 如果你再做這樣的事情，就會(huì)受到懲罰。

　　⑶、If I should work harder, I could make much more progress.假如我更努力學(xué)習(xí)的話，我會(huì)取得更大的進(jìn)步。(事實(shí)上我不可能努力學(xué)習(xí))

　�、�、If it should rain tomorrow, I would stay at home.如果明天下雨的話，我將待在家里。(根據(jù)天氣情況，明天不可能下雨)

　�、�、If he should come, I could ask him for some advice.萬(wàn)一他來(lái)了，我就能夠向他請(qǐng)教。(事實(shí)上他來(lái)的可能性很小)

　�、�、If he came tomorrow, I would do it with him.如果明天他來(lái)的話，我將和他一起做此事。(事實(shí)上他來(lái)的可能性很小)

　　⑺、 If it should rain, the crops would be saved.(從句動(dòng)詞用should rain，主句動(dòng)詞用be)如果天下雨，莊稼可能就收獲了。

　�、�、 If he were to go fomorrow, he might tell you.(從句動(dòng)詞用were to, 主句動(dòng)詞用tell)如果明天他走的話，他可能會(huì)告訴你。

　�、�、 If he were here, I would give him the books.(從句動(dòng)詞用were, 主句動(dòng)詞用give)如果他在這兒，我可能會(huì)把書給他。

　　注意：如果動(dòng)作在進(jìn)行中，從句(不是主句喔)要用："If + 主語(yǔ)+ 過(guò)去進(jìn)行式動(dòng)詞 +……"

　�、�、 If she were staying here now, I would let her ride my horse.(從句動(dòng)詞用were staying, 主句動(dòng)詞用let)如果她現(xiàn)在留在這兒，我可能會(huì)讓她騎我的馬。