虛擬語氣動詞的虛擬語氣表示

1、虛 擬 語 氣動詞的虛 擬語氣表示說話人的愿望、假設(shè)、猜測或建議，而不表示客觀存在的事實。虛 擬語氣通過謂語動詞的特殊形式來表示。（一）虛 擬語氣用于簡單 句表示祝愿、命令等，謂語動詞要用原形。1.不帶任何助動詞。例如： God bless you . 上帝 保佑你! 2.用may 。例如：May our friendship further develop .愿我們的友誼天長地久。 May you enjoy a ripe old age.祝您晚年幸福！3.用wish 。 例如：Wish you good health.祝您健康。4）用Long live 。Long live peace a

2、nd friendship .和平與友誼萬歲！(二)虛 擬語氣用于條件句表示一種不能實現(xiàn)或?qū)崿F(xiàn)可能性特別小的“非真實條件”.通常有下列三種時態(tài):1.與現(xiàn)實相反的假設(shè) 條件句： 動詞用過去時 主 句: should /could /would /might +動詞原形注意:在條件句中be的過去式一般用were。1）If he were there , all would be well . 如果他在那兒,一切都好辦了。2）I would tell her if I thought she would understand . 如果我認(rèn)為她能理解的話,我就會告訴她了。2.與過去事實相反的假設(shè) 表示

3、與過去事實相反的假設(shè),往往帶有“可惜”、 “理應(yīng)” 、 “懊悔”等惋惜、責(zé)備的含義。條件句： had +過去分詞主 句 should /would /could /might /+have +過去分詞1）If the policeman had arrived earlier ，he would have seen the accident. .如果警察早來一步, 就會看到這場 事故了。1）If you had spoken clearly ，you would have been understood. 如果你說得清楚的話, 你早被理解了。虛 擬 語 氣(2) “were+動詞不定式”型所表

4、示的事情在三種形式中發(fā)生的可能性最小。條件句：were +動詞不定式主 句：情態(tài)動詞的過去式+動詞原形If John were to do the experiment tomorrow，he might read the instructions carefully.約翰想明天做那個試驗,他也許會把那些指令仔細(xì)地讀一遍。（3）“動詞過去式”型條件句：動詞過去式+表示將來時間的狀語主 句：情態(tài)動詞的過去式+動詞原形1）If it were Sunday tomorrow，I would go to see my teacher .要是明天是星期天,我會去看那兒的老師。（三）使用虛擬語氣的常見句

5、型1. It +be +某些形容詞或過去分詞+（that） +從句主語+（should） +動詞原型+常用于這一句型的詞有necessary,important,impossible,strange,natural,essential等;常用于此的過去分詞表示提議、要求或命令等,有suggested, requested, demand, proposed, ordered, advised, urged, insisted等。1）It is necessary that you （should）be present at the meeting.務(wù)必請你出席會議。2)It is natura

6、l the he (should) say so . 他這樣說是很自然的。2. 用在decide ,advice,require ,ask,intend,suggest,order,demand,proposecommand,request,desire,insist等表示建議、命令、要求的動詞引導(dǎo)的賓語從句中。謂語用（should）+動詞原形。例如：1)I propose it (should) be done at once.我提議立即做這件事。使用虛擬語氣的常見句型II3.用在advice, suggestion, motion, order, plan等后面的同位語從句中或以它們?yōu)橹髡Z

7、的表語從句中，（should）+動詞原形。1) His advice that you (should) go over the plan once more is reasonable.他要你把計劃再檢查一遍的檢驗是有道理的。2）What I advise is that you go and ring him up.我的意見是你去給他打個電話。4.用在It is （high/about） time （that）的從句中。 從句中用過去時。例如：1）It is time we left . 我們該離開了。Its high /about time that we began our class

8、 .我們馬上該上課了。與將來事實相反的假設(shè)表示說話人對尚未發(fā)生的事進(jìn)行推測，對條件的實現(xiàn)認(rèn)為不可能。（1）最常用的形式條件句： should +動詞原形 主 句；should/would/might + 動詞原形 1）If he should consider the problem again ,he might get a correctconclusion. 如果他把那個問題再考慮一遍,他也許會得到一個正確的結(jié)論。2）If she should come ，I should/would ask her for help.如果她來的話,我就請她幫忙。4. 省略連詞if的條件從句如果條件從句

9、的謂語中含有were,、had、should，可以省略if, 將were、 had、 should放在主語之前構(gòu)成倒裝句。例如：1）Were I you，I would take an umbrella with me . 如果我是你,我會帶一把傘的。2) Had she been given some information , she could have answered the question 如果給她提供一些資料的話,她可以回答這些問題的。3）Should he fail to come ，John would work in his place 。萬一他不來，約翰將代替他工作。t

10、hough 引導(dǎo)的讓步狀語從句從句用were、動詞過去式或動詞原形。主句用should/ could+動詞原形或陳述語氣。例如：1）Though it rained heavily，I will be off雖然雨下得很大，我還是要走。 2）Though he were a teacher，he would obey the rule. 即使他是一個領(lǐng)導(dǎo)，也得遵守這個規(guī)則。 6.even if /though引導(dǎo)的狀語從句從句：過去式或had+過去分詞。主 句：should/would+動詞原形或have+過去分詞。1）Even if he were present at the meetin

11、g ，I should say the same thing.即使他參加會議，我還是這樣說。（與現(xiàn)在事實相反，時態(tài)前移一次，即用過去時。）Even though he had looked for me ，he couldnt have found me。I was out yesterday.他即使找也找不到我，我昨天出去了。（與過去事實相反，時態(tài)前移一次，用過去完成時）7.在however，whatever，wherever，whenever及no matter what 等引導(dǎo)的狀語從句中，從句：動詞原形或may+動詞原形，若指過去時間，則用may+have+過去分詞主 句：陳述語氣1)

12、 However poor one may be, one can always find something to be thankful for.一個人不管多窮，他總是可以找到一些可以欣慰的 東西。2）We mustnt be proud no matter what achievements we may have made.不論取得多么大的成績，我們都不能驕傲。8.在as if/though引導(dǎo)的比較狀語從句中，動詞用過去式或had+過去分詞。1) He looks as if he were a child.他看起來象個小孩。2)They acted as if nothing ha

13、d happened.他們表現(xiàn)得好象什么也沒有發(fā)生似的。3)It seems as though it was going to rain.好象要下雨似的。注意：as if/though從句時態(tài)總是將真實情況（既陳述語氣時應(yīng)有的）時態(tài)前移一次。9.在in order that/ so that引導(dǎo)的目的狀語從句中,謂語是may/might/can/could+動詞原形1) She listened carefully in order that she might discover exactly what he wanted.她仔細(xì)地聽著，以便發(fā)現(xiàn)他究竟想要什么。2) She died so

14、 that others might live.她為了別人而犧牲了。10.在for fear that,lest, in case引出的消極目的的狀語從句中，謂語是(should)+動詞原形1) I left the note for fear that (lest)you should forget.我怕你忘記才留下這張便條。2) Youd better leave the key at home in case one of us (should) think of coming back.你最好把鑰匙留在家里，以防我們中間有人想回來。注意： lest 與 for fear that 本意

15、都有“怕”的意思，而lest多用于書面語， for fear that 卻較通俗； in case 含有“防備”的意思，口語中常用in case 代替lest。11.與would 連用的一些詞組1）would rather 其后的賓語從句必須用一般過去時。例如：She would rather you left next month instead of tomorrow.她寧愿讓你下月而不是明天動身走。 2）would as soon as 與would sooner than 二者都與would rather 意義相同，但要用動詞原形。例如：1）She would as soon stay

16、 in the classroom as go to the room. 她寧愿留在教室而不去房間。2）She would sooner carry on the research work than give it up.她寧愿繼續(xù)進(jìn)行這項研究工作而不愿放棄。 12.Wish后面的賓語從句用虛擬語氣Wish后面的賓語從句表示愿望。表示與現(xiàn)實相反的 ，從句用過去時表示與過去事實相反的，從句用過去完成時。例如：1）I wish I were a bird .（與現(xiàn)在事實相反）我真希望我是一只鳥2）She wishes she hadnt said it .（與過去事實相反）她真希望她沒說過這話。3）He says that he could fly to the moon .（與現(xiàn)實相反）他說他真可以飛到月球上去就好。在Without（如果沒有），but for（要不是）介詞短語后的簡單句中，也可用虛擬語氣。Without和but for 相當(dāng)于表示將來時間的條件句。例如：1）Without your help （=If it were not for her ），I might not be able to solve the problem .如果沒有