語(yǔ)法專攻略六

1、1．“must＋動(dòng)詞原形”用于肯定句中，表示肯定推測(cè)或判斷，有“一定”之意?！狪t's the office！So you must know eating is not allowed here.(2009年高考湖南卷)——這是辦公室！所以你一定知道這里不許吃東西?！狾h，sorry.——噢，對(duì)不起。,2．can用于肯定句中有時(shí)可以用來(lái)表示推測(cè)，意為“有時(shí)會(huì)”；用于疑問(wèn)句中可以表示推測(cè)，意為“可能”，有時(shí)表示一種驚訝的

2、語(yǔ)氣；用于否定句中也可以表示推測(cè)，can't意為“不可能”，語(yǔ)氣很強(qiáng)烈。It is usually warm in my hometown in March，but it can be rather cold sometimes.我的家鄉(xiāng)在三月份通常很暖和，但有時(shí)候也會(huì)相當(dāng)冷。Don't play with the dog，Jack，for it can be dangerous at times.杰克，不要逗狗

3、玩，因?yàn)楣酚袝r(shí)是危險(xiǎn)的。There is no light in the room.She can't be at home now.房間里沒(méi)有燈光。她現(xiàn)在不可能在家里。,3．may，might用于肯定句中可以用來(lái)表示推測(cè)，意為“可能”；用于否定句中也可以表示推測(cè)，may not意為“可能不”，表示一種不太確定的語(yǔ)氣。—Is there an express to Beijing tonight?——今晚有去北京的快車嗎

4、？—There might be，but you'd better call the booking office to make sure.——可能有，不過(guò)你最好給訂票處打電話確認(rèn)一下。4．should用來(lái)表示推測(cè)時(shí)意為“應(yīng)該”，即含有“按道理來(lái)說(shuō)應(yīng)當(dāng)如此”的意思。The public transport in Beijing is very convenient，so there shouldn't be a

5、ny difficulty in traveling around the city.現(xiàn)在北京的公共交通非常便利，所以在市區(qū)觀光不應(yīng)該有什么困難。,1．must表示“偏執(zhí)，固執(zhí)”If you must smoke，please go outside.如果你非要抽煙，請(qǐng)到外面去。(2011年高考大綱全國(guó)卷)2．“may as well＋動(dòng)詞原形”意為“最好，滿可以，倒不如”—If you think the price of t

6、he coat is too high，you may as well buy a cheaper one.——如果你認(rèn)為這件外衣價(jià)格太高，你不妨買一件便宜的外衣?！狪t depends on you.——你自己決定。,3．shall(1)表示命令、許諾、警告、強(qiáng)制、威脅、決心等，一般用于第二、三人稱中，并用于陳述句。According to the school rules，no student shall go out o

7、f the school after eleven o'clock at night without the teacher's permission.根據(jù)學(xué)校規(guī)定，未經(jīng)老師許可任何學(xué)生夜間11點(diǎn)后不允許外出?！狪 haven't got the reference book yet，but I'll have a test on the subject next month.——我至今還沒(méi)有拿到參

8、考書(shū)，但是下個(gè)月這個(gè)學(xué)科就要測(cè)試了。—Don't worry.You shall have it by Friday.——?jiǎng)e擔(dān)心，周五之前你一定會(huì)有的。,(2)用于征求對(duì)方的意見(jiàn)或指示，用在第一、三人稱的疑問(wèn)句中?！狧as Mr.Wang arrived?——王先生到了嗎？—Yes，already.Shall he wait outside or just come in?—是的，已經(jīng)到了。他是進(jìn)來(lái)，還是在外面等？

9、4．will與would表示自愿做或主動(dòng)提出做什么，如意志、愿望或決心等。(1)would用于過(guò)去的情況。After hours of repair，the driver tried to start the machine，but it wouldn't work.經(jīng)過(guò)幾個(gè)小時(shí)的修理，司機(jī)試著發(fā)動(dòng)汽車，但是它仍無(wú)法啟動(dòng)。,John promised his doctor he would not smoke，and he

10、 has never smoked ever since.約翰答應(yīng)醫(yī)生不再吸煙了，并且從那時(shí)起他再也不吸煙了。(2)would表示過(guò)去常常When we worked in the same firm several years ago，we would often go to the cinema together.當(dāng)幾年前我們?cè)谕患夜竟ぷ鲿r(shí)，我們常常一起去電影院。,1．can/could have done表示“本來(lái)可以

11、做，而實(shí)際上未做”或者“過(guò)去可能”，疑問(wèn)或否定形式表示對(duì)過(guò)去發(fā)生的行為表示懷疑或不肯定，其中can't have done多用于語(yǔ)氣強(qiáng)烈的否定，意為“不可能做過(guò)”。She can't have left school，for her bike is still here.她的自行車仍然在這兒，她不可能離開(kāi)學(xué)校了。2．needn't have done表示本來(lái)不必做某事而實(shí)際上卻做了。I actually

12、needn't have bought so much wine—only three people came.其實(shí)我本沒(méi)必要買這么多酒，只來(lái)了三個(gè)人。,3．must have done表示對(duì)過(guò)去行為的推測(cè)，意為“一定，想必”，語(yǔ)氣十分肯定。It must have been Tom that parked the car here，as he is the only one with a car.一定是湯姆把車停在這里的

13、，因?yàn)橹挥兴熊嚒?．should/ought to have done用于肯定句時(shí)，表示本該做某事，而實(shí)際上未做；用于否定句時(shí)，則表示不該做的事反而做了。I'm not feeling well in the stomach.I shouldn't have eaten so much fried chicken just now.我現(xiàn)在覺(jué)得肚子疼，我剛才不應(yīng)該吃那么多的炸雞。,5．may/might have

14、done表示對(duì)過(guò)去行為的推測(cè)，意為“可能做過(guò)”。might所表示的可能性比較弱，語(yǔ)氣較委婉。此處might have done可表示“本可能做而實(shí)際上未做”?！猈hy didn't Alex attend the party yesterday evening?——為什么Alex昨晚沒(méi)參加晚會(huì)？—He might not have wanted to see me.——他有可能不想見(jiàn)到我。,1.混合虛擬語(yǔ)氣有時(shí)主句和

15、虛擬條件從句的動(dòng)作發(fā)生的時(shí)間不一致，此時(shí)，主句和從句的謂語(yǔ)動(dòng)詞要根據(jù)各自所指的不同時(shí)間選擇適當(dāng)?shù)膭?dòng)詞形式。If he hadn't hurt his legs in the last training，he would join in the coming World Cup，which he has been longing to compete in.要是在上次訓(xùn)練中他的腿沒(méi)受傷的話，他會(huì)參加他渴望已久的世界杯。2．含

16、蓄虛擬語(yǔ)氣有時(shí)為了表達(dá)的需要，假設(shè)的情況并不以If條件句表示出來(lái)，而是通過(guò)but for，without，otherwise，or等介詞、副詞暗含在上下文中。I was caught in a traffic jam for over an hour，otherwise I would not have kept you waiting for such a long time.交通堵塞了一個(gè)多小時(shí)，否則我不會(huì)讓你等這么長(zhǎng)時(shí)間。,

17、But for your help，it would have caused a serious loss.要不是你的幫助，那將會(huì)導(dǎo)致巨大的損失。3．若條件句中有were，had，should，可把if省略，而把were，had，should放在主語(yǔ)前，形成倒裝結(jié)構(gòu)，這種結(jié)構(gòu)主要用于書(shū)面語(yǔ)中。Had you taken my advice，you wouldn't have failed in the examinatio

18、n.如果你聽(tīng)了我的建議，你就不會(huì)考試不及格了。4．if only引導(dǎo)的感嘆句中，要求用虛擬語(yǔ)氣，表示愿望。Look at the trouble we're in.If only we had taken our teacher's advice!看看我們現(xiàn)在所處的困境，要是我們接受老師的建議就好了。,5．It is( high/about)time(that)．..句型中的虛擬語(yǔ)氣?！猅om，it's

19、 high time you took the medicine.—Thank you for reminding me，I almost forgot it.——Tom，該是你服藥的時(shí)間了?！兄x你提醒我，我?guī)缀醵纪恕?．would rather句型中的虛擬語(yǔ)氣表示愿望，意為“寧愿，但愿”?！狣o you mind if we set out earlier tomorrow morning?—Well，I'd

20、 rather you didn't.——我們明天早晨早出發(fā)你介意嗎？——我寧愿你不早出發(fā)。,7．wish后面所跟賓語(yǔ)從句中的虛擬語(yǔ)氣。表示對(duì)現(xiàn)在情況的虛擬：wish＋主語(yǔ)＋動(dòng)詞過(guò)去式或were表示對(duì)過(guò)去情況的虛擬：wish＋主語(yǔ)＋had＋過(guò)去分詞表示對(duì)將來(lái)情況的虛擬：wish＋主語(yǔ)＋would＋動(dòng)詞原形—Do you know his address?—No，I also wish I knew where he

21、 lives.——你知道他的地址嗎？ ——不，要是我知道他住在什么地方就好了。,8．在名詞性從句中，常用來(lái)表示命令、建議、要求、愿望等的詞后賓語(yǔ)從句和同位語(yǔ)從句中用虛擬語(yǔ)氣，形式為：(should)＋動(dòng)詞原形。常這樣用的動(dòng)詞有：advise勸告，demand要求，desire渴望，command命令，insist堅(jiān)持，prefer寧愿，urge主張，order命令，recommend推薦，request要求，require要