英語(yǔ)虛擬語(yǔ)氣一直受到語(yǔ)言學(xué)家及語(yǔ)法學(xué)家們的關(guān)注。他們從各個(gè)方面對(duì)虛擬語(yǔ)氣進(jìn)行了分析，包括給虛擬語(yǔ)氣下定義，進(jìn)行分類，討論其在交際中的功能，甚至也爭(zhēng)論其存在的價(jià)值，而隨著語(yǔ)言學(xué)發(fā)展，虛擬語(yǔ)氣的意義構(gòu)建成為研究重點(diǎn)。學(xué)好虛擬語(yǔ)氣對(duì)于學(xué)習(xí)英語(yǔ)的整體有著極大的幫助!

　　英語(yǔ)虛擬語(yǔ)氣學(xué)習(xí)指導(dǎo)1.虛擬語(yǔ)氣在條件句中的用法

　　(1)若表示與現(xiàn)在事實(shí)相反的假設(shè)，則條件從句中用過(guò)去式，主句中用過(guò)去將來(lái)式(would，should，could，might + 動(dòng)詞原形);若表示某事將來(lái)實(shí)現(xiàn)的可能性不大，則條件從句中用should + 動(dòng)詞原形也可用“were to+動(dòng)詞原形”或用過(guò)去式動(dòng)詞。

　　I would certainly go if I had time.(現(xiàn)在)

　　If it should rain，we wouldn’t go out.(將來(lái))

　　If I knew German，I would read the paper to you.(現(xiàn)在)

　　If he were here，we could ask him.(現(xiàn)在)

　　(2)若表示與過(guò)去事實(shí)相反的假設(shè)，從句中用過(guò)去完成式，主句中用過(guò)去將來(lái)完成式(should，would，could，might + have + 過(guò)去分詞)。

　　If Ihad set off a little earlier，I would have caught the train.

　　Shewould / might have come if she hadn’t been so busy.

　　If I hadn’t taken your advice，I wouldhave made a bad mistake.

　　If only you hadn’t told him the news.

　　(3)含有虛擬語(yǔ)氣的條件狀語(yǔ)從句中，如有had，should，were這三個(gè)詞的話，在正式或書面語(yǔ)言中可將if省略，再將句子的主語(yǔ)和謂語(yǔ)動(dòng)詞實(shí)行全部倒裝或部分倒裝。如：

　　Had they time(=If theyhad time)，they would certainly come and help us.

　　Should it be fine(=If it should be fine)，we would go for an outing.

　　Were I go(=If Iwere you)，I would go.

　　(4)若主句從句所指的時(shí)間不一致，即條件從句表示與過(guò)去事實(shí)相反，主句表示與現(xiàn)在事實(shí)相反;或者條件從句表示與現(xiàn)在事實(shí)相反，主句表示真實(shí)情況，則從句中應(yīng)采用與具體時(shí)間相對(duì)應(yīng)的虛擬形式。

　　If ithad rained last night(過(guò)去)，It would be very cold today(現(xiàn)在).

　　If Ihad taken your advice(過(guò)去)，I should have no trouble with the work now(現(xiàn)在).

　　英語(yǔ)虛擬語(yǔ)氣學(xué)習(xí)指導(dǎo)2. 條件句中的虛擬語(yǔ)氣的舉例

　　(1) 將來(lái)時(shí)的條件句中的虛擬語(yǔ)氣。

　　If he should go to Qing Hua University, he would make full use of his time. 如果他要上清華大學(xué)的話，他就會(huì)充分利用他的時(shí)間了。

　　If he were to come here, he would tell us about it. 如果他要來(lái)的話，他會(huì)通知我們一聲。

　　(2) 現(xiàn)在時(shí)的條件句中的虛擬語(yǔ)氣。

　　If he were free, he would help us. 要是他有空的話，它會(huì)幫助我們的。

　　If he studied at this school, he would know you well. 如果他在這所學(xué)校學(xué)習(xí)的話，它會(huì)對(duì)你很熟悉。

　　(3) 過(guò)去時(shí)的條件句中的虛擬語(yǔ)氣。

　　If I had seen the film, I would have told you about it. 我如果看過(guò)這場(chǎng)電影，我會(huì)把電影內(nèi)容告訴你了。

　　If I had got there earlier, I would have met Mr. Li. 如果我早點(diǎn)到那兒，我就會(huì)會(huì)到了李先生。

　　英語(yǔ)虛擬語(yǔ)氣學(xué)習(xí)指導(dǎo)3. 運(yùn)用條件句中的虛擬語(yǔ)氣時(shí)，須注意的幾個(gè)問(wèn)題

　　(1) 當(dāng)從句的主語(yǔ)為第三人稱單數(shù)時(shí)，謂語(yǔ)動(dòng)詞若是系動(dòng)詞be時(shí)，可用was 代替were。但在倒裝虛擬結(jié)構(gòu)及if I were you, as it were中，只能用were。

　　Were I ten years younger, I would study abroad. 要是我還年輕十歲的話，我會(huì)去國(guó)外學(xué)習(xí)。

　　If I were you, I would try my best to grasp the chance. 要是我是你的話，我要盡力抓住這次機(jī)會(huì)。

　　(2) 有時(shí)，虛擬條件句中，主、從句的動(dòng)作若不是同時(shí)發(fā)生時(shí)，須區(qū)別對(duì)待。

　?、?gòu)木涞膭?dòng)作與過(guò)去事實(shí)相反，而主句的動(dòng)作與現(xiàn)在或現(xiàn)在正在發(fā)生的事實(shí)不符。

　　If I had worked hard at school, I would be an engineer, too. 如果我在學(xué)校學(xué)習(xí)刻苦的話，我現(xiàn)在也會(huì)使工程師了

　　If they had informed us, we would not come here now. 如果他們通知過(guò)我們的話，我們現(xiàn)在就不會(huì)來(lái)這里了。

　?、趶木涞膭?dòng)作與現(xiàn)在事實(shí)相反，而主句的動(dòng)作與過(guò)去事實(shí)不符。

　　If he were free today, we would have sent him to Beijing. 如果他今天有空的話，我們會(huì)已經(jīng)派他去北京了。

　　If he knew her, he would have greeted her. 要是他認(rèn)識(shí)她的話，他肯定會(huì)去問(wèn)候她了。

　?、蹚木涞膭?dòng)作與過(guò)去發(fā)生的情況相反，而主句的動(dòng)作與現(xiàn)在正在發(fā)生的情況相反。

　　If it had not been raining too much, the crops would be growing much better. 如果天不下太多的雨的話，莊家會(huì)長(zhǎng)得更好。

　　If he had been working hard, he would be working in the office now. 要是他工作一直努力的話，他現(xiàn)在已進(jìn)了辦公室了。

　　英語(yǔ)虛擬語(yǔ)氣學(xué)習(xí)指導(dǎo)4、虛擬語(yǔ)氣的用法及動(dòng)詞形式

　　一、表示與現(xiàn)在事實(shí)相反的情況：

　　從句：If 主語(yǔ)+過(guò)去時(shí)(Be動(dòng)詞用were)

　　主句：主語(yǔ)+should/would/could/might+do

　　eg：

　　1.If I were you,I would take an umbrella.

　　如果我是你，我會(huì)帶把傘。(事實(shí)：我不可能是你)

　　2.If I knew his telephone number,I would tell you.

　　如果我知道他的電話號(hào)碼，我就會(huì)告訴你。(事實(shí)：不知道)

　　3.If there were no air or water,there would be no living things on the earth.

　　如果沒(méi)有水和空氣，地球上就不會(huì)有生物。(事實(shí)：地球上既有空氣也有水)

　　4.If I had any money with me,I could lend you some.

　　如果我?guī)уX了，我就會(huì)借給你些。(事實(shí)：沒(méi)有帶錢)

　　5.If he studied harder,he might pass the exam.

　　如果他再努力些，就能通過(guò)考試了。(事實(shí)：沒(méi)有努力)

　　(注意：一般在虛擬的條件句中無(wú)論是第幾人稱，用到系動(dòng)詞的過(guò)去式時(shí)，只用were而不用was)

　　二、表示與過(guò)去事實(shí)相反的情況

　　從句：If 主語(yǔ)+had+done

　　主句：主語(yǔ)+should/would/could/might+have done

　　eg：

　　1. If I had got there earlier,I should/could have met her. 如果我早到那兒，我就會(huì)見(jiàn)到她。

　　(事實(shí)：去晚了)

　　2.If he had taken my advice,he would not have made such a mistake. 如果他聽(tīng)我的勸告的話，就不會(huì)犯這樣的錯(cuò)誤了。

　　(事實(shí)：沒(méi)有聽(tīng)我的話)

　　3.she looked at me as if I had been a stranger.

　　她看我的樣子好像我是一個(gè)陌生人。(事實(shí)：我并非陌生人)

　　三、表示對(duì)將來(lái)情況的主觀推測(cè)

　　主句：主語(yǔ)+would+do

　　從句：①if+主語(yǔ)+were to do

　　②if+主語(yǔ)+should/would/could/might+do

　?、踚f+主語(yǔ)+did(動(dòng)詞過(guò)去式)/were

　　eg：

　　1.If he should come here tomorrow,I would talk to him.

　　如果他明天來(lái)這兒的話，我就跟他談?wù)劇?事實(shí)：來(lái)的可能性很小)

　　2.If there were a heavy snow next Sunday,we would not go skating.

　　如果下周日下大雪，我們就不能去滑冰了。(事實(shí)：下雪可能性很小)

　　3.If she were to be here next Monday,I would tell her about the matter.

　　如果她下周一來(lái)這兒的話，我就會(huì)告訴她這件事的始末。(事實(shí)：來(lái)的可能性很小)

　　四、 有時(shí)，虛擬條件句中，如果主句和條件從句的謂語(yǔ)動(dòng)作若不是同時(shí)發(fā)生時(shí)，虛擬語(yǔ)氣的形式應(yīng)作出相應(yīng)的調(diào)整。這種條件句叫錯(cuò)綜條件句。

　　①?gòu)木涞膭?dòng)作與過(guò)去事實(shí)相反，而主句的動(dòng)作與現(xiàn)在或現(xiàn)在正在發(fā)生的事實(shí)不符。

　　eg：

　　If I had worked hard at school,I would be an engineer,too.

　　如果我在學(xué)校學(xué)習(xí)刻苦的話，我現(xiàn)在也會(huì)成為一個(gè)工程師了

　　If they had informed us,we would not come here now.

　　如果他們通知過(guò)我們的話，我們現(xiàn)在就不會(huì)來(lái)這里了。

　?、趶木涞膭?dòng)作與現(xiàn)在事實(shí)相反，而主句的動(dòng)作與過(guò)去事實(shí)不符。

　　如：

　　If he were free today,we would have sent him to Beijing.

　　如果他今天有空的話，我們會(huì)已經(jīng)派他去北京了。

　　If he knew her,he would have greeted her.

　　要是他認(rèn)識(shí)她的話，他肯定會(huì)去問(wèn)候她了。

　　五、 當(dāng)虛擬條件句的謂語(yǔ)動(dòng)詞含有were,should,had時(shí)，if可以省略，這時(shí)條件從句要用倒裝語(yǔ)序，即把were,should,had等詞置于句首，這種多用于書面語(yǔ)。eg：

　　Should he agree to go there,we would send him there.

　　要是他答應(yīng)去的話，我們就派他去。

　　Were she here,she would agree with us.

　　如果她在這兒的話，她會(huì)同意我們的。

　　Had he learnt about computers,we would have hired him to work here.

　　如果他懂一些電腦知識(shí)的話，我們已經(jīng)聘用他來(lái)這里工作了。

　　六、非真實(shí)條件句中的條件從句有時(shí)不表達(dá)出來(lái)，只暗含在副詞、介詞短語(yǔ)、上下文或其他方式表示出來(lái)，這種句子叫做含蓄條件句，在多數(shù)情況下，條件會(huì)暗含在短語(yǔ)中，如without…，but for…等

　　eg：

　　But for his help,we would be working now.

　　要不是他的幫助，我們還會(huì)在工作呢。

　　Without your instruction,I would not have made such great progress.

　　要是沒(méi)有你的指導(dǎo)，我不會(huì)取得如此大的進(jìn)步。

　　We didn't know his telephone number,otherwise,we would have telephoned him.

　　我們不知道他的電話號(hào)碼，否則我們就會(huì)給他打電話。

　　七、 有時(shí)，虛擬條件句中，主、從句可以省略其中的一個(gè)，來(lái)表示說(shuō)話人的一種強(qiáng)烈的感情。

　?、偈÷詮木?/p>

　　He would have finished it. 他本該完成了。

　　You could have passed this exam. 你本能通過(guò)這次考試的。

　?、谑÷灾骶?/p>

　　If I were at home now. 要是我現(xiàn)在在家里該多好啊。

　　If only I had got it. 要是只有我得到它了該多好啊。

　　八.注意，在虛擬語(yǔ)氣的從句中，動(dòng)詞be的過(guò)去時(shí)態(tài)一律用were，不用was。

　　eg：If I were you,I would go to look for him.

　　如果我是你，就會(huì)去找他。