動(dòng)詞的語(yǔ)氣——虛擬語(yǔ)氣(The Subjunctive Mood)
一、語(yǔ)氣的定義和種類
l、語(yǔ)氣：語(yǔ)氣是動(dòng)詞的一種形式,它表示說(shuō)話人對(duì)某一行為或事情的看法和態(tài)度.
2、語(yǔ)氣的種類：
(1)陳述語(yǔ)氣: 表示動(dòng)作或狀態(tài)是現(xiàn)實(shí)的、確定的或符合事實(shí)的,用于陳述句、疑問句和某些感嘆句.如：We are not ready. 我們沒準(zhǔn)備好.What a fine day it is!多好的天氣啊!
(2)祈使語(yǔ)氣: 表示說(shuō)話人的建議、請(qǐng)求、邀請(qǐng)、命令等.如: Open the door, please.請(qǐng)打開門.
(3)虛擬語(yǔ)氣: 表示動(dòng)作或狀態(tài)不是客觀存在的事實(shí),而是說(shuō)話人的主觀愿望、假設(shè)或推測(cè)等.如: If I were you, I should study English. 如果我是你,我就學(xué)英語(yǔ)了.May you succeed! 祝您成功!
二、虛擬語(yǔ)氣在條件從句中的用法
條件句有兩類,一類是真實(shí)條件句,一類是虛擬條件句.如果假設(shè)的情況是有可能發(fā)生的,就是真實(shí)條件句.在這種真實(shí)條件句中的謂語(yǔ)用陳述語(yǔ)氣.如: If it doesn’t rain tomorrow, we will go to the park. 如果明天不下雨,我們就去公園.
如果假設(shè)的情況是過(guò)去或現(xiàn)在都不存在的,或?qū)?lái)不大可能發(fā)生的,則是虛擬條件句.如: If he had seen you yesterday, he would have asked you about it. 如果他昨天見到你,他會(huì)問你這件事的.(事實(shí)上他昨天沒見到你,因此也未能問你這件事.)
在含有虛擬條件句的復(fù)合句中,主句和從句的謂語(yǔ)都要用虛擬語(yǔ)氣.現(xiàn)將虛擬條件從句和主句的動(dòng)詞形式列表如下:

與現(xiàn)在事實(shí)相反:從句: 動(dòng)詞的過(guò)去式（be的過(guò)去式一般用were）
主句:would/ should/ could/ might + 動(dòng)詞原形
與過(guò)去事實(shí)相反 : 從句 :had + 過(guò)去分詞
主句 :would/ should/ could/ might + have + 過(guò)去分詞
與將來(lái)事實(shí)相反 :從句:動(dòng)詞過(guò)去式,should + 動(dòng)詞原形,
主句 :were to + 動(dòng)詞原形 would/ should/ could/ might + 動(dòng)詞原形
注: 主句中的should只用于I、we,但在美國(guó)英語(yǔ)中,should常被would代替；從句中的should可用于各種人稱.
l、表示與現(xiàn)在事實(shí)相反的假設(shè)和結(jié)果.如: If my brother were here, everything would be all right. 要是我哥哥在這兒 ,一切都沒問題了.
2、表示與過(guò)去事實(shí)相反的假設(shè)和結(jié)果.如: If you had taken my advice,you wouldn't(couldn’t) have failed in the exam. 如果你按照我的建議去做,你一定不會(huì)(不可能)考試不及格.
3、表示與將來(lái)事實(shí)可能相反的假設(shè)和結(jié)果.如: If it were Sunday tomorrow, I should (would,could,might) go to see my grandmother. 如果明天是星期天,我就 (可能)去看望我奶奶.If it were to snow this evening, they would not go out. 如果今晚下雪,他們將不出去了.
4、有時(shí)條件從句中的動(dòng)作和主句中的動(dòng)作發(fā)生的時(shí)間不一致（表示錯(cuò)綜時(shí)間的虛擬語(yǔ)氣）,這時(shí)動(dòng)詞的形式要根據(jù)它所表示的時(shí)間加以調(diào)整.例如: If you had listened to the doctor, you would be all right now. 如果你當(dāng)初聽了醫(yī)生的話,身體現(xiàn)在就好了.(從句動(dòng)作指過(guò)去,主句動(dòng)作指現(xiàn)在)
5、虛擬條件句可以轉(zhuǎn)換成下列形式:
(l)省略連詞if.在書面語(yǔ)中,如果虛擬條件從句中有were,had 或 should,可以把if省略,把這幾個(gè)詞放到主語(yǔ)之前,構(gòu)成主謂倒裝.例如: Should he come (If he should come), tell him to ring me up. 他要是來(lái)了,讓他給我打個(gè)電話.Were I you (If I were you), I would not do it. 我要是你,就不做這事.
(2)用介詞短語(yǔ)代替條件狀語(yǔ)從句.有時(shí)假設(shè)的情況并不用條件從句表示出來(lái),而是通過(guò)介詞短語(yǔ)來(lái)表示.如: Without air (If there were not air), there would be no living things. 如果沒有空氣的話,就不會(huì)有生物了.But for your help (If it hadn’t been for your help) I couldn’t have done it. 要是沒有你的幫助,我就不可能完成這件事.
假設(shè)的情況有時(shí)可以通過(guò)上下文或其他方式表現(xiàn)出來(lái).如: I was busy that day. Otherwise I would have gone there with them. (If I hadn’t been busy that day, I would have gone there with them.) 我那天很忙,否則,我就和他們一起去那兒了.(如果我那天不忙的話,我就……)；I would have finished the work, but I have been ill. (If I hadn’t been ill, I would have finished the work.) 我本來(lái)該完成這項(xiàng)工作的,但我生病了.(如果我沒生病的話,我就會(huì)完成……)
6、省去條件從句或主句：表示虛擬語(yǔ)氣的主句或從句有時(shí)可以省略,但其含義仍可以推知.
(1)省去條件從句.如: You could have washed your clothes yourself. 你本可以自已洗衣服的.省去了"If you had wanted to")(事實(shí)是:你自己沒洗衣服,因?yàn)槟悴幌胂?)
(2)省去主句(常用以表示愿望).如: If my grandmother were with me! 如果我的祖母與我在一起多好啊!(事實(shí)是:祖母已不在世.)；If only she had not left! 如果她沒走就好了!(事實(shí)是:她已經(jīng)走了.)
三、虛擬語(yǔ)氣的其他用法
l、虛擬語(yǔ)氣在主語(yǔ)從句中的用法：在"It is important (strange,natural,necessary)that…"這類句型里,that所引導(dǎo)的主語(yǔ)從句中的謂語(yǔ)動(dòng)詞常用 “should+動(dòng)詞原形”結(jié)構(gòu),表示某事是"重要"、"奇怪"、"自然"、"必要"等意義.如: It is important that every member (should) inform himself of these rules. 重要的是每個(gè)成員知道這些規(guī)則.
2、虛擬語(yǔ)氣在賓語(yǔ)從句中用法：
(1)在動(dòng)詞wish后的賓語(yǔ)從句中,表示與現(xiàn)在或過(guò)去的事實(shí)相反,或?qū)?lái)的主觀愿望,從句通常省略連詞that.1)表示對(duì)現(xiàn)在情況的虛擬:從句動(dòng)詞用過(guò)去式或過(guò)去進(jìn)行式(be動(dòng)詞一般用were).如: I wish I knew the answer to the question. 我希望知道這個(gè)問題的答案.(可惜不知道)；2）表示對(duì)過(guò)去情況的虛擬:從句動(dòng)詞常用"had+過(guò)去分詞".如: I wish (wished) I hadn’t spent so much money. 我后悔不該花那么多錢.(實(shí)際上已經(jīng)花掉)；3)表示對(duì)將來(lái)的主觀愿望:謂語(yǔ)動(dòng)詞形式為"would+動(dòng)詞原形".此時(shí)要注意,主句的主語(yǔ)與從句的主語(yǔ)不能相同,因?yàn)橹骶涞闹髡Z(yǔ)所期望的從句動(dòng)作能否實(shí)現(xiàn),取決于從句主語(yǔ)的態(tài)度或意愿(非動(dòng)物名詞除外).如: I wish it would stop raining. 但愿雨能停止；I wish you would come soon. 但愿你立刻來(lái).
(2)在suggest,demand,order,propose,insist,command,request,desire等動(dòng)詞后的賓語(yǔ)從句中,謂語(yǔ)動(dòng)詞用“should + 動(dòng)詞原形”,表示建議、要求、命令等.如: I demand that he (should) answer me immediately. 我要求他立刻答復(fù)我.
3、虛擬語(yǔ)氣在狀語(yǔ)從句中的用法
(1)在帶有even if/ even though引導(dǎo)的讓步狀語(yǔ)從句的主從復(fù)合句中,主句和從句都用虛擬語(yǔ)氣,動(dòng)詞形式與含有非真實(shí)條件句的虛擬語(yǔ)氣相同.如: Even if he had been ill, he would have gone to his office. 即使生了病,他都去辦公室.
(2)由as if或as though引導(dǎo)的狀語(yǔ)從句表示比較或方式時(shí).從句謂語(yǔ)形式為動(dòng)詞的過(guò)去式(be用were)或 “had+過(guò)去分詞”.如: He treated me as if I were a stranger. 他那樣對(duì)待我,好像我是陌
生人似的.She talked about the film as if she had really seen it. 她談?wù)撃遣坑捌?就好像她確實(shí)看過(guò)一樣.
注:如果表示的事情可能會(huì)發(fā)生,那么方式狀語(yǔ)從句中的謂語(yǔ)動(dòng)詞可用陳述語(yǔ)氣.
(3)在in order that或so that引導(dǎo)的目的狀語(yǔ)從句中,謂語(yǔ)動(dòng)詞多用 “could或might（有時(shí)也用should）+ 動(dòng)詞原形”.如: Mr green spoke slowly so that his students could (might) hear clearly. 格林先生說(shuō)得很慢,好讓學(xué)生聽清楚.
4、虛擬語(yǔ)氣在定語(yǔ)從句中的用法：在"It is time (that) …"句型中,定語(yǔ)從句的謂語(yǔ)動(dòng)詞常用虛擬語(yǔ)氣表示將來(lái),動(dòng)詞形式一般用過(guò)去式,意思是"該干某事的時(shí)候了".如: It’s (high) time we did our homework. 我們?cè)撟?a href="http://villageglobe.com/" target="_blank">作業(yè)了.
5、虛擬語(yǔ)氣在簡(jiǎn)單句中的用法
(1)情態(tài)動(dòng)詞的過(guò)去式用于現(xiàn)在時(shí)態(tài)時(shí),表示說(shuō)話人的謙虛、客氣、有禮貌,或委婉的語(yǔ)氣,常見于日常會(huì)話中.如: It would be better for you not to stay up too late. 你最好別太晚睡覺.
(2)在一些習(xí)慣表達(dá)中.如: I would rather not tell you. 我寧愿不告訴你.
(3)用“may + 動(dòng)詞原形”表示"祝愿"、"但愿”,此時(shí)may須置于句首（多用于正式文體中）.如：May you be happy!祝你快樂!May good luck be yours.祝你順利.