虛擬語氣
虛擬語氣用來表示說話人的主觀愿望或假想，而不表示客觀存在的事實(shí)，所說的是一個(gè)條件，不一定是事實(shí)，或與事實(shí)相反。虛擬語氣通過謂語動(dòng)詞的特殊形式來表示。英語中的語氣分為陳述語氣、祈使語氣、虛擬語氣三類。
什么時(shí)候用虛擬語氣
在表示假想的虛假的、與事實(shí)相反的或難以實(shí)現(xiàn)的情況時(shí)用虛擬語氣，
虛擬語氣表示主觀愿望或某種強(qiáng)烈情感時(shí)，也用虛擬語氣。即當(dāng)一個(gè)人說話時(shí)欲強(qiáng)調(diào)其所說的話是基于自己的主觀想法，愿望，假想，猜測(cè)，懷疑或建議，而不是根據(jù)客觀實(shí)際，就用虛擬語氣。主要是英語語法的一種表達(dá)，與真實(shí)語氣相對(duì)。
表示虛擬語氣的幾個(gè)句型
條件狀語：條件句可分為兩類，一類為真實(shí)條件句，一類為非真實(shí)條件句。非真實(shí)條件句表示的是假設(shè)或?qū)嶋H可能性不大的情況，故采用虛擬語氣。
例如：
If he doesn't hurry up,he will miss the bus.如果他不快點(diǎn)，他將錯(cuò)過巴士。( 真實(shí))
If he is free,he will ask me to tell stories.如果他是空閑的，他會(huì)要求我講故事。(真實(shí))
If I were you,I would go at once.如果我是你，我馬上就會(huì)去。(我不可能是你。非真實(shí)，虛擬語氣，與現(xiàn)在事實(shí)相反)
If there were no air,people would die.如果沒有空氣，人就會(huì)死亡。(不可能沒有空氣。非真實(shí)，虛擬語氣，與現(xiàn)在事實(shí)相反)
1、表示與現(xiàn)在事實(shí)相反的情況：
從句：If+主語+過去時(shí)(Be動(dòng)詞用were)
主句：主語+ should/would+do：
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)：沒有帶錢)
5.If he studied harder,he might pass the exam.
如果他再努力些，就能通過考試了。(事實(shí)：沒有努力)
6.If I were you, I'd wear a shirt and tie.
如果我是你，我就會(huì)穿襯衫和領(lǐng)帶。(事實(shí)：我并不是你)
2、表示與過去事實(shí)相反的情況
從句：If+主語+had+done
主句：主語+should/would+have done
eg：
1. If I had gotten there earlier,I should/would have met her. 如果我早到那兒，我就會(huì)見到她。
(事實(shí)：去晚了)
2.If he had taken my advice,he would not have made such a mistake. 如果他聽我的勸告的話，就不會(huì)犯這樣的錯(cuò)誤了。
(事實(shí)：沒有聽我的話)
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)
3、表示對(duì)將來情況的主觀推測(cè)
從句：①if+主語+were to do (if 表示未來的虛擬語氣獨(dú)有該形式，其他如wish， even if等詞都沒有該形式來表示未來的虛擬語氣)
?、趇f+主語+should+do
?、踚f+主語+過去式(be動(dòng)詞用were)
主句：主語+should/would+do
eg：
1.If he should come here tomorrow,I would talk to him.
如果他明天來這兒的話，我就跟他談?wù)劇?事實(shí)：來的可能性很小，不可能)
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，不可能)
3.If she were to be here next Monday,I would tell her about the matter.
如果她下周一來這兒的話，我就會(huì)告訴她這件事的始末。(事實(shí)：來的可能性很小，不可能)
4、 有時(shí)，虛擬條件句中，結(jié)果主句和條件從句的謂語動(dòng)作若不是同時(shí)發(fā)生時(shí)，虛擬語氣的形式應(yīng)作相應(yīng)的調(diào)整。這種條件句叫錯(cuò)綜條件句。
?、購木涞膭?dòng)作與過去事實(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.
如果他們通知過我們的話，我們現(xiàn)在就不會(huì)來這里了。
?、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)去問候她了。
5、 當(dāng)虛擬條件句的謂語動(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序，即把were,should,had等詞置于句首，這種多用于書面語。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)聘用他來這里工作了。
6、非真實(shí)條件句中的條件從句有時(shí)不表達(dá)出來，只暗含在副詞、介詞短語、上下文或其他方式表示出來，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。
7、 有時(shí)，虛擬條件句中，主、從句可以省略其中的一個(gè)，來表示說話人的一種強(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. 你本能通過這次考試的。
②省略主句
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。
8.注意，在虛擬語氣的從句中，動(dòng)詞be的過去時(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。
3目的狀語1、在for fear that,in case,lest引導(dǎo)的從句中，若用虛擬語氣時(shí)，從句謂語為：should + do。并且should能省略
She examined the door again for fear that a thief (should) come in.
她又把門檢查了一遍，以防盜賊的進(jìn)入。
He started out earlier lest he (should) be late.
他早早的就出發(fā)了以防遲到。
2、在so that,in order that所引導(dǎo)的目的狀語從句中，從句中的謂語為：can / could / may / might / will / would / should + do。
He goes closer to the speaker so that he can hear him clearer. 他走近說話的人以便能聽得更清楚。
He read the letter carefully in order that he should not miss a word. 他把信讀得很仔細(xì)以便不漏掉一個(gè)字。
賓語從句：[1]一、I wish后的賓語從句
動(dòng)詞wish后接賓語從句時(shí)，從句謂語要用虛擬語氣。若要表示與現(xiàn)在事實(shí)相反的愿望，從句謂語用一般過去時(shí)或過去進(jìn)行時(shí)(同樣be動(dòng)詞換成were);若表示與過去相反的愿望，從句謂語用would / could+have +過去分詞或者過去完成時(shí)had done;若表示將來沒有把握或不太可能實(shí)現(xiàn)的愿望，用would (could)+動(dòng)詞原形。
注意如果將wish改為過去式wished, 其后that 從句中的動(dòng)詞形式不變。
如：
I wish I could be of some use. 我希望我能有什么用處。
We wish he didn’t smoke. 我們希望他不吸煙。
I wish prices would come down. 我希望物價(jià)能降下來。
I wish the train would come. 我希望火車會(huì)來。
I wished I hadn't spent so much money. 但愿我并沒有造成太多的破費(fèi)。
二、表示“堅(jiān)持”后的賓語從句
主要是指insist的賓語從句，從句謂 語由“should+動(dòng)詞原形”構(gòu)成，其中的should在美國 英語中通?？梢允÷?。如：
I insisted that he (should) stay. 我堅(jiān)持要他留下。
He insisted that I (should) go with them. 他堅(jiān)持要我同他們一起去。
Rose insisted that he be present. 羅斯堅(jiān)持要他出席。
The detective insisted that he should have a look. 警探堅(jiān)持要查看。
注意：動(dòng)詞insist后接賓語從句時(shí)，除可用虛擬語氣外，也可用陳述語氣，兩者的區(qū)別是：若謂語動(dòng)詞所表示的動(dòng)作尚未發(fā)生，或尚未成為事實(shí)，則用虛擬語氣;若謂語動(dòng)詞所表示的動(dòng)作已經(jīng)發(fā)生，或已經(jīng)成為事實(shí)，則要用陳述語氣。比較：
He insisted that I had read his letter. 他堅(jiān)持說我看過他的信。
He insisted that I should read his letter. 他堅(jiān)持要我看他的信。
三、表示“命令”后的賓語從句
主要是指order, command的賓語從句，從句謂語由“should+動(dòng)詞原形”構(gòu)成，其中的should在美國英語 中通?？梢允÷?。如：
He ordered that it (should) be sent back. 他命令把它送回去。
Thejudge ordered that the prisoner should be remanded. 法官命令被告還押。
The King ordered that the man be released. 國王命令釋放那人。
He commanded that we (should) attack at once. 他命令我們立即發(fā)起進(jìn)攻。
四、表示“建議”后的賓語從句
主要是指advise, suggest, propose, recommend等的賓語從句，從句 謂語由“should+動(dòng)詞原形”構(gòu)成，其中的should在美國英語中通?？梢允÷浴Ｈ纾?/p>
He suggested that we should leave early. 他建議我們?cè)琰c(diǎn)動(dòng)身。
The doctor advised that he change his job. 醫(yī)生勸他換工作。
They recommend that this tax be abolished. 他們建議取消這種稅。
I suggest that we (should) have lunch right now. 我建議我們現(xiàn) 在就吃午飯。
The committee proposed (that) Mr. Day be elected. 委員會(huì)建議推選戴先生。
The doctor advised [suggested] that he (should) not smoke. 醫(yī)生建議他不要抽煙。
I propose that the matter be put to the vote at once. 我提議對(duì)此問題立刻進(jìn)行表決。
He proposed that Mr. O’Leary be the chairman. 他提議奧列利先生擔(dān)任主席。
She suggested that I (should) be responsible for the arrangements. 她建議我來負(fù)責(zé)進(jìn)行安排。
注意：與動(dòng)詞insist相似，動(dòng)詞suggest后接賓語從句時(shí)，除可用虛擬語氣外，也可用陳述語氣，兩者的區(qū)別也是：若謂語動(dòng)詞所表示的情況尚未成為事實(shí)，則用虛擬語氣，此時(shí)suggest通常譯為“建議”;若謂語動(dòng)詞所表示的情況為既成事實(shí)，則要用陳述語氣，此時(shí)的suggest通常譯為“表明”、“認(rèn)為”。比較并體會(huì)：
He suggested that we (should) stay for dinner. 他建議我們留下吃飯。
What he said suggested that he was a cheat. 他說的話表明他是個(gè)騙子。
I suggested that you had a secret understanding with him. 我覺得你與他心照不宣。
五、表示“要求”后的賓語從句
主要是指ask, demand, require, request等后的賓語從句，從句謂語 由“should+動(dòng)詞原形”構(gòu)成，其中的should在美國英語中通常 可以省略。如：
I ask that he leave. 我要求他走開。
He requires that I (should) appear. 他要求我出場(chǎng)。
They require that I go at once. 他們要求我立刻走。
I demand that John (should) go there at once. 我要求約翰立即到那里去。
I requested that he should use his in fluence on my behalf. 我請(qǐng)求他為我施用他的影響。
He asked that the message be given to Madame immediately. 他要求把信息立即帶給夫人。
They demanded that the right to vote be given to every adult man. 他們要求給予每個(gè)成年男子以選舉權(quán)。
六、表示“提議”“投票”后的賓語從句
主要是指move, vote等后的賓語從句，從句謂語由“should+動(dòng)詞原形”構(gòu)成，其中的should在美國英語中通常可以省略。如：
I move that we accept the proposal. 我提議通過這項(xiàng)提案。
Mr. Chairman, I beg to move that the meeting be adjourned. 主席先生，我提議休會(huì)。
Congress has voted that the present law be maintained. 國會(huì)投票決定維持現(xiàn) 在這條法律。
Claudel moved that Norwood should be made a member of the committee. 克洛戴爾提出動(dòng)議，讓諾伍德當(dāng)一名委員。
七、表示“敦促”后的賓語從句
主要是指動(dòng)詞urge后的賓語從句，從句謂語由“should+動(dòng)詞 原形”構(gòu)成，其中的should在美國英語中通?？梢允÷浴Ｈ纾?/p>
He urges that the restrictions be lifted. 他敦促取消這些限制。
He urged that they go to Europe. 他敦促他們到歐洲去。
He urged that the rates should be reduced. 他敦請(qǐng)減輕捐稅。
He urged that the matter should go to arbitration. 他極力主張這件事要提交仲裁。
They urged that relief work should be given priority. 他們敦促將救濟(jì)工作放在優(yōu)先位置。
八、表示“安排”后的賓語從句
主要是指動(dòng)詞arrange后的賓語從句，從句謂語由“should+動(dòng)詞原形”構(gòu) 成，其中的should在美國英語中通常可以省略。如：
He arranged that I should go abroad. 他安排我去國外。
I arranged that Tom should meet them. 我安排好叫湯姆去接他們。
They arranged that the minister should be met at the airport. 他們安排在機(jī)場(chǎng)迎接這位部長(zhǎng)。
It was arranged that they should leave the following spring. 已安排好他們第二年春天離開。
They’ve arranged that I should absent myself for part of the meeting. 他們安排好讓我一部分時(shí)間不在開會(huì)現(xiàn)場(chǎng)。
九、表示“希望”“打算”后的賓語從句
主要是指動(dòng)詞desire, intend后的賓語從句，從句謂語由“should+動(dòng)詞原形”構(gòu)成，其 中的should在美國英語中通?？梢允÷?。如：
She desires that he do it. 她希望他做此事。
They intended that the news (should) be suppressed. 他們打算封鎖這條消息。
I desire the patient should have a bath every day. 我希望病人每天洗澡。
十、表示“指示”后的賓語從句
主要是指動(dòng)詞direct后的賓語從句，從句謂語由“should+動(dòng)詞原形”構(gòu)成，其中的should在美國英語中通常可以省略。如：
The general directed that the prisoners should be set free. 將軍指示釋放那些俘虜。
虛擬語氣的用法
1、一想要(desire) 一寧愿(prefer) 一堅(jiān)持(insist)二命令(order , command) 三建議(advise , suggest , propose/recommend) 四要求(demand , require , request , ask)中，無論主句謂語動(dòng)詞為何種時(shí)態(tài)，從句的謂語動(dòng)詞都用："should + do"。should可以省略。
eg：He suggested that we (should) take the teacher's advice.
He insisted that we (should) take the teacher's advice.
He demand that we (should) take the teacher's advice.
He ordered that we (should) take the teacher's advice.
insist意為“堅(jiān)持某種動(dòng)作”才用虛擬語氣;意為“堅(jiān)持某種觀點(diǎn)，某個(gè)事實(shí)”則不用虛擬語氣。
eg：
He insists he is a student.
他堅(jiān)持說他是個(gè)學(xué)生。
這個(gè)語句表示的是事實(shí)，因此在這個(gè)語句中不能使用虛擬語氣。
suggest意為“建議”才用虛擬語氣，意為“暗示”則不用虛擬語氣。
eg：
His face suggests that he looks worried .
他的表情暗含著他很擔(dān)心。
這個(gè)句子本身是事實(shí)，因此它就沒有用到虛擬語氣。
2、表情緒.觀點(diǎn)的形容詞或名詞也要用虛擬語氣.如：necessary、important、impossible、natural、strange、surprising、funny、right、wrong、better、a pity ,the shame ,no wonder等。
句型：It is.......that +主語從句，從句的謂語動(dòng)詞都要用should+原型或只用動(dòng)詞原型。
eg:
Do you think it is necessary that he (should)not be sent to Lingbao.
It is strange that such a person should be our friend.
奇怪的是這樣一個(gè)人會(huì)成為我們的朋友。
注：這一點(diǎn)還沒有準(zhǔn)確的說法，希望善心人能把這點(diǎn)補(bǔ)充完全。
3、 在even if,even though 所引導(dǎo)的讓步狀語從句中用may/might+動(dòng)詞原形，may/might可以省略，表示與現(xiàn) 在相反的情況;從句用過去完成時(shí)，表示與過去相反的情況，類似的詞有though/even though/whatever/however/so long as; 主句、從句的結(jié)構(gòu)與if所引導(dǎo)的條件從句結(jié)構(gòu)相同。
eg：
Even if he were here himself,he should not know what to do.
即使他親自來也不知該怎么辦。(事實(shí)：他沒來)
Nobody could save him even though Hua Tuo should come here.
即使華佗在世也救不了他。(事實(shí)：華佗不在世)
4、 在whatever，whichever，whenever，whoever,wherever，however,no matter wh-等引導(dǎo)的讓步狀語從句中，從句虛擬語氣結(jié)構(gòu)為：
指現(xiàn) 在或?qū)恚簃ay +do。
eg：
We will finish it on time no matter what may happen.
不管發(fā)生什么事，我們都要按時(shí)完成。
We will find him wherever he may be.
無論他在哪里，我們都要找到他。
I will wait for him no matter how late he may come.
不管他來的多么晚，我都會(huì)等他。
指過去：may +have done。
eg：
You mustn't be proud whatever great progress you may have made.
不管你取得了多么大的進(jìn)步，你也不能驕傲。
We must respect him no matter what mistakes he may have made.
不管他犯過什么錯(cuò)誤，我們必須尊敬他。
5、一般would rather,had rather,would sooner等之后的賓語從句常表示與客觀事實(shí)不相符的一種愿望，故使用虛擬語氣。其虛擬語氣的結(jié)構(gòu)為：
過去 had + done
現(xiàn) 在 過去時(shí)(be 用were )
將來 過去時(shí)(be 用were ) (would rather將來情況用一般過去時(shí))
eg：
I'd rather you had seen the film yesterday.
我倒想你昨天看過了這場(chǎng)電影。
I'd rather you were here now.
我倒想你現(xiàn)在在這兒。
We'd rather you went here tomorrow.
我們倒想你明天去那兒
注：注意would rather，had rather，would sooner的細(xì)微差別，可以百度一下查查。
6、虛擬語氣還可用在定語從句中，表示：“早該做某事了”時(shí)，定語從句中的謂語動(dòng)詞須用虛擬語氣，其虛擬語氣的結(jié)構(gòu)為：It is (high / about) time that + 主語+ 動(dòng)詞的過去式/ should + do(優(yōu)先使用動(dòng)詞過去式)，即從句用虛擬過去式。
It is time that I went to pick up my daughter at school.
我該去學(xué)校接我的女兒了。
It is high time you should go to work.
你早該上班了。
7、 簡(jiǎn)單句中的虛擬語氣
(1) 說話時(shí)，為了表示客氣、謙虛、委婉而有禮貌，言語常使用虛擬語氣。其虛擬語氣的結(jié)構(gòu)形式常為：would / could / might / should +do。
eg：
Would you mind me shutting the door?
你介意我把門關(guān)起來嗎?
You should always learn this lesson by heart.
你要把這個(gè)教訓(xùn)牢記于心。
I should agree with you.
我本該同意你的觀點(diǎn)。(委婉的不同意)
(2)表示“祝愿”時(shí)，常用may +主語+ do。
eg：
May you have a good journey!
祝你一路順風(fēng)。
May your youth last forever!
祝你青春永駐。
(3)表示強(qiáng)烈的“愿望”、“祝愿”時(shí)，常用do。
eg：God bless us. 上帝保佑。
(4)習(xí)慣表達(dá)中常用的虛擬語氣。
?、?提出請(qǐng)求或邀請(qǐng)。eg：
Would you like to have a talk with us this evening?
今天晚上來跟我們聊天好嗎?
Could I use your bike now?
我可以用一下你的單車嗎?
?、?陳述自己的觀點(diǎn)或看法。eg：
I should be glad to meet you.
見到你我會(huì)很高興。
I would try my best to help you.
我會(huì)盡力幫助你。
?、厶岢鰟窀婊蚪ㄗh。eg：
You'd better ask your father first.
你最好先問一問你的父親。
You should make a full investigation of it first.
你應(yīng)該先全面調(diào)查一番。
④ 提出問題。eg：
Do you think he could get here on time
你認(rèn)為他能按時(shí)來嗎?
Do you expect he would tell us the truth?
你期望他會(huì)告訴我們真相嗎?
⑤表示對(duì)過去情況的責(zé)備時(shí)，常用虛擬語氣。其虛擬語氣的結(jié)構(gòu)為：情態(tài)動(dòng)詞+ have done。
eg：
You should have got here earlier. 你早該到這里了。
You should have returned it to him. 你早該把它還給他了。
8、虛擬語氣在方式狀語從句的應(yīng)用。詳見百度百科之方式狀語從句詞條。
