2022年高中英語語法專項(xiàng)復(fù)習(xí) 十四、英語語法 情態(tài)動(dòng)詞 實(shí)用學(xué)案 新人教版情態(tài)動(dòng)詞，在英文中主要用來表示說話人的看法、態(tài)度等。它很接近中文里的能愿動(dòng)詞。從用法上來說，它有這樣幾個(gè)特點(diǎn)：1）各個(gè)情態(tài)動(dòng)詞自身都有一定的詞義。2）情態(tài)動(dòng)詞不能在句中獨(dú)立擔(dān)當(dāng)謂語。3）情態(tài)動(dòng)詞在句中不受任何人稱,性,數(shù)變化的影響。4) 情態(tài)動(dòng)詞后接的不定式（除ought外）都不帶to ，即接動(dòng)詞原形。英文中的情態(tài)動(dòng)詞主要有：can , could ; may , might ; must ; ought ; need ; dare , dared ，另外，shall , will , should , would在一定的場(chǎng)合也可用作情態(tài)動(dòng)詞。例如：He can speak five languages .他會(huì)說五種語言。 She must have arrived home by now .現(xiàn)在她準(zhǔn)到家了。We should study hard for our motherland . 我們應(yīng)該為祖國(guó)而努力學(xué)習(xí)。They needn't be in such a hurry for there is enough timefor them . 他們還有足夠的時(shí)間，用不著這么慌張。 1. 常用情態(tài)動(dòng)詞的基本用法can , could 能，會(huì)（could可以看作是can的過去式，這兩個(gè)詞除了時(shí)態(tài)不相同外，在表達(dá)意思的許多方面是相同的。當(dāng)然could也有自己獨(dú)特的用法。）1）表示腦力或體力上的能力Nobody can stop the development of science .誰也無法阻止科學(xué)的發(fā)展。She can sing that song in English.她能用英文唱那歌。He can submerge to a depth of about twenty meters .他能潛入約二十米深的水中。He could hardly support his family before he found the new job .他在找到那份新工作前幾乎無 法養(yǎng)家。I could not understand the lecture on the puter given by Mr. Smith .我聽不懂史密斯先生作的那個(gè)關(guān)于計(jì)算機(jī)的講座。2)表示客觀上的可能性You can borrow this useful book from the library .你可以從圖書館借到這種有用的書。A more suitable person than him for the job can not be found . 不可能找到比他更適合這份工作的人了。Now people can skate on the lake .現(xiàn)在人們可以在湖上滑冰了。When the storm stopped , the plane could take off .當(dāng)風(fēng)暴停下來時(shí)，飛機(jī)可以起飛了不得。3)表示主觀上的允許Can I ask you some questions about it ? 我可以問你有關(guān)這件事的幾個(gè)問題嗎？You can not leave here till I e back .直到我回來你才能離開。Such kind of thing can't happen any more later . 這類事以后不準(zhǔn)再發(fā)生了。Can you tell me how to get to the airport ? 你能告訴我怎么去機(jī)場(chǎng)嗎？ Could you tell me how to get to the airport ? 您能告訴我怎么去機(jī)場(chǎng)嗎？Could I be forgiven my negligence ? 請(qǐng)?jiān)徫业氖韬?，行嗎?）（用于否定句、疑問句或感嘆句中）表示猜測(cè)、懷疑或驚詫How can / could you be here ? 你怎么會(huì)在這兒？She couldn't / can't be so stupid to do that .她不可能蠢得去做那種事吧。He couldn't / can't be over seventy .他不可能有七十多歲了。Where could / can the boy be now ? 那孩子現(xiàn)在能在哪兒呢？另外，could還常用于表示較客氣委婉的看法、提問及用于虛擬語氣的結(jié)構(gòu)中。這時(shí)候，could就不可以看作是can的過去式了。而是could自己獨(dú)特的用法。如：Could you speak a little slowly ? 您能稍微說慢一點(diǎn)兒?jiǎn)?？I'm afraid that we couldn't give you any definite answer at this moment .恐怕我們這時(shí)候還無法給予您任何確切的答復(fù)。I could e earlier if asked .如果要讓我早一點(diǎn)來，我可以來早一點(diǎn)。We would appreciate it if you could offer us any help . 如果您能為我們提供幫助的話，我們將不甚感激。You could have done better if you had worked harder at it . 如果你再加把勁，本來可以干得更好一些的。may , might 或許，可能，可以（might可以看作是may的過去式，這兩個(gè)詞除了時(shí)態(tài)不相同外，在表達(dá)意思的許多方面是相近的。當(dāng)然may 和might又都有一些各自不同的獨(dú)特用法。）1）可能性 I may be busy from tomorrow on .從明天起我可能會(huì)忙起來。You may catch sight of the sunrise from here when you get up before 5 in the morning .你在早晨五點(diǎn)鐘以前起來，或許能從這兒看到日出。I wondered if they might agree with the idea .我想知道他們是否會(huì)同意這種想法。 She thought it might be wise to try her luck here .她認(rèn)為在這兒碰碰運(yùn)氣也不錯(cuò)。2）表示允許 May I e in ? 我可以進(jìn)來嗎？I'd like to have a smoke here if I may .如果可以的話我想在這兒抽一支煙。The librarian told her that she might return the book to the library in three days .圖書館理員告訴她說，她可以在三天后還那本書。At the press conference , a news reporter asked the chairman if she might trouble him with a question about Taiwan issue. 在記者招待會(huì)上，一位新聞?dòng)浾邌柎髸?huì)主席她是否能提一個(gè)有關(guān)臺(tái)灣問題方面的問題。3) may間或用來表示祝愿，也常用于表示目的或讓步的狀語從句中: May that day e soon .但愿這天早日到來。May you succeed in winning the first prize in the game .祝愿你比賽奪冠成功。May you continue in your efforts and achieve greatersuccesses .祝愿你繼續(xù)努力并取得更大的成功。4) might也常用于表示目的等狀語從句中，或用于虛擬語氣的結(jié)構(gòu)中:I could not convince him , try as I might .我無論用什么樣的辦法也不能說服他。They left off earlier on that day so that they might catch the first train .那天，他們?yōu)榱粟s上頭班車動(dòng)身早一些。He died so that the others might live .為了其他的人能活下去，他自己犧牲了。If you had made better use of your time , you might have learned more .假若你將自己的時(shí)間利用得更好一些，你本可以學(xué)到更多東西的。One error in calculation might ruin the whole project .計(jì)算中出一點(diǎn)錯(cuò)就可能毀掉整個(gè)工程。注意：在回答以may引導(dǎo)的問句時(shí)，一般說來避免使用may，以免顯得太嚴(yán)厲、或不太客氣，而改用其他方式。例如：-May I e in ? -Yes , please .請(qǐng)進(jìn)。我可以進(jìn)來嗎？ -Sure . / Certainly . .請(qǐng)進(jìn)。-Please don't . .請(qǐng)不要進(jìn)來。-No , you mustn't .不行。must 應(yīng)該，必須，一定1) 表示出于職責(zé)、義務(wù)該做某事 We must protect people's rights .我們應(yīng)該保護(hù)人民的利益。Everyone must be loyal to his motherland .每個(gè)人都應(yīng)該忠于自己的祖國(guó)。You must serve the people when you grow up .你們長(zhǎng)大成人時(shí)應(yīng)該服務(wù)于人民。Students must work hard at their study .學(xué)生應(yīng)該努力學(xué)習(xí)。2）表示出于主觀意識(shí)而必須要做某事We must speed up the pace of our economic reform .我們必須加速經(jīng)濟(jì)改革的步伐。We must keep steps to the scientific development .我們一定要與科學(xué)的發(fā)展保持一致步調(diào)。You must hurry up or you'll be late .你必須得快點(diǎn)兒，不然會(huì)遲到的。在這種用法中must表示出于主觀意識(shí)而必須要做某事；have to卻表示由于某種客觀原因而不得不做某事。除此以外，have to自身有時(shí)態(tài)的變化形式。如：I have to go now for I've got a meeting 15 minutes later.我現(xiàn)在必須要走了，因?yàn)槲?5分鐘后有個(gè)會(huì)要開。He has to be back home by five to fetch his son from kindergarten .他必須在五點(diǎn)鐘前回家去幼兒園接他的兒子。Jenny had to tidy up the room before her mother came back .珍尼不得不在她媽媽回家以前將房間整理好。We'll have to reconsider the whole thing .我們將不得不重新考慮整個(gè)事情。注意：在這種用法中，回答以must引導(dǎo)的問句時(shí)，若是否定答復(fù)，不可以用mustn't 而需要用needn't 或是don't have to，因?yàn)閙ustn't意思是"絕不能、一定不要"，而沒有"不必"的意思。例如：-Must we hand in our exercises today ? 我們今天必須交作業(yè)嗎？-Yes , you must .是的，必須交。-No , you needn't (or , you don't have to ).不，不必今天交。3）表示禁止（用于否定句）You must not speak ill of others .你一定不要說別人的壞話。Cars must not parked here . 這里禁止停車。Smoking must not allowed in the office .嚴(yán)禁在辦公室吸煙。You mustn't talk to girls like that .你絕不能那樣對(duì)女孩子說話。4）表示猜測(cè)、推測(cè)must常用于肯定句中表示猜測(cè)。對(duì)現(xiàn)在或未來的事進(jìn)行猜測(cè)時(shí)，后接動(dòng)詞原形；對(duì)已經(jīng)發(fā)生的事進(jìn)行猜測(cè)時(shí)，后接have + 過去分詞。例如：You must be tired after working so long .你工作這么久以后，肯定累了吧。It must be that naughty boy crying outside .肯定是那個(gè)調(diào)皮的孩子在外面大叫。The idea must be accepted by the society sooner or later.這種想法肯定或遲或早會(huì)被社會(huì)所接受的。It must have rained last night for it is so wet outside .外面這么濕，昨晚肯定下雨了。I didn't see you in class yesterday. You must have beenabsent .我昨天上課沒見著你，你肯定沒有來。Ought （后接帶to的不定式構(gòu)成謂語動(dòng)詞）應(yīng)該1）表示出于職責(zé)、義務(wù)該做某事You ought not to be so careless in your work .你不應(yīng)該在工作上如此粗心大意。We ought to study hard for the sake of our motherland.我們應(yīng)該為了我們的祖國(guó)而努力學(xué)習(xí)。His doctor said to him that he oughtn't to smoke so much .他的大夫說他不應(yīng)該抽這么多煙。Oughtn't you to give us a chance to try ?你難道不應(yīng)該給我們一個(gè)嘗試的機(jī)會(huì)嗎？2) 表示極有可能發(fā)生某事As an auto repairman , Dick ought to know what is wrong with the car .狄克作為一個(gè)汽車修理工總該知道這部車的毛病所在吧。If we set off right now , we ought to be able to get there in time .如果我們馬上出發(fā)，我們應(yīng)當(dāng)能夠按時(shí)到達(dá)那里。Tomorrow ought to be a nice day for we have such a fine sunset today .今天有這么好的晚霞，明天準(zhǔn)是個(gè)晴天。need（用于否定句和疑問句）需要There are still one and a half hours to go , we needn't be insuch a hurry .還有一個(gè)半小時(shí)，我們無需如此慌慌張張。I hardly need say how much we missed you .不用說我們是多么想念你啊。Need you go so soon ?你需要這么早就去嗎？You need have no anxiety on my account .你不必為我而著急。dare , dared（用于否定句、疑問句和疑問句）敢Dare you stay here alone in the night ? 你敢在夜里呆在這兒?jiǎn)?？Nobody dared mention that matter. 沒有人敢提那件事。How dared you say that to her ? 你怎么敢對(duì)她說那件事？Even if you dare do it , I won't allow you to because it's too dangerous .即使你敢做，我也會(huì)讓你做那件事，因?yàn)樘ｋU(xiǎn)了shall 用作情態(tài)動(dòng)詞時(shí),適用于第二人稱和第三人稱。主要表示下面幾層意思： 1）許諾You shall hear everything directly you e .你一來就可以聽到一切了。"Whatever you want you shall have , "said the Fairy .仙女說："你想得到什么，你就可以有什么。"I don't want to be hard on your daughter ; she shan't be pressed .我不想對(duì)你女兒太嚴(yán)厲，她不會(huì)太受壓的。I promise that you shall see her again before long .我保證你不久就能再見到她。2）命令You shall e to my office immediately .你必須馬上來我的辦公室。She shall not stay in my garden .她不可以呆在我的花園里。He shall not e into my study . 不許他進(jìn)我的書房。You shall do as you are told .按告訴你的那么做。3）決心（表示某事一定會(huì)發(fā)生）That day shall e .那一天一定會(huì)到來。It has been decided that he shall be given the job .肯定給他那份工作的事已經(jīng)定下來了。This law shall e into effect on January 1st xx 這個(gè)法律于xx年元月1日生效。4）規(guī)定Each petitor shall wear a number .每個(gè)參賽者要佩戴一個(gè)數(shù)字標(biāo)。The renter shall keep the house in a neat and orderly state . 租賃者要保持房屋整潔有序。The supplier shall make shipment before October and the purchaser shall make payment within 15 days after receipt of the goods .賣方十月以前裝運(yùn)，買方在收到貨物后十五天內(nèi)付款。should （用作情態(tài)動(dòng)詞時(shí)，有時(shí)表示具體的意思，有時(shí)卻沒有意義。主要用于下面幾個(gè)方面。）1）表示出于職責(zé)、義務(wù)該做某事You shouldn't e to such a decision hastily .你不應(yīng)該匆匆忙忙地作出這么一個(gè)決定。You should write to your parents at least once a month .你應(yīng)該至少每月給你父母親寫一封信。We should read English aloud every morning .我們應(yīng)該每天早晨朗讀英文。They should do it for their own good .為了他們自己利益他們應(yīng)該做這件事。2）表示對(duì)某種情況的估計(jì)She shouldn't be out in such an early morning .她不會(huì)這么一大早就出去了吧。The effect of the tax should be felt in higher prices .人們可能會(huì)從各種上漲的物價(jià)中感覺到這種稅的影響的。The event should lead them to a even worse economic crisis.這次事件可能會(huì)將他們引向更嚴(yán)重的經(jīng)濟(jì)危機(jī)。This book should be published in two months at most .這本書最多兩個(gè)月后就會(huì)出版的。3）表示驚訝、失望等情緒I think it is dreadful that anyone should be so miserable.我認(rèn)為，竟然每個(gè)人都如此傷心就太糟糕了。Why should I pay him for nothing ? 我干嗎要無為地付給他錢？It seems so unfair that this should happen to me .這件事竟然發(fā)生在我身上似乎太不公平了。It's strange that it should be so cold today .奇怪，今天怎么會(huì)這么冷。4）用于某些從句中表示虛擬語氣The doctor insisted that the girl should be hospitalized .大夫堅(jiān)持認(rèn)為那個(gè)女孩要住院治療。If it had not been for the doctor's care the girl should not be speaking to you now .要不是由于大夫的精心照料，這個(gè)女孩現(xiàn)在就不能與你說話了。She stood away so that he should enter the room first .她讓到一邊，好讓他第一個(gè)進(jìn)入房間。I'll write it down lest I should forget it 我將它記下以免遺忘。Take an umbrella with you in case it should rain .帶上雨傘，以防萬一下雨。will , would（would可以看作是will的過去式，這兩個(gè)詞除了時(shí)態(tài)不相同外，在表達(dá)意思的許多方面是相近的。當(dāng)然will 和would又都有一些各自不同的獨(dú)特用法。）1）用于第二人稱疑問句，表示請(qǐng)求（在這種用法中would使語氣更為客氣、委婉）Will you tell her that I'll be back in twenty minutes ? 請(qǐng)告訴她我二十分鐘后回來，好嗎？If you want help, just let me know , will you ? 你需要幫助就告訴我，好嗎？Won't you e in and have a little whisky ? 你要不要進(jìn)來喝一點(diǎn)兒威士忌？（或是：你進(jìn)來喝一點(diǎn)兒威士忌，好嗎？）Would you tell me how to get to the shopping center ? 您能告訴我怎么去購物中心嗎？2）用于表示愿望Go where you will .去你想去的地方吧。I will pay you at the rate you ask .我會(huì)按你要的利率付給你錢的。He wouldn't let the doctor take his blood pressure .他不愿意讓大夫給他量血壓。They had to obey whether they would or not .他們不得不遵從他們的意愿。3）表示習(xí)慣、傾向（可譯成"總是會(huì)、老是，等" ）Sometimes the cat will lie there all afternoon .有時(shí)侯，那只貓總是整個(gè)下午都躺在那兒。Oil and water will not mix .油和水決不能調(diào)和。He would sit there for hours , doing nothing at all . 他總是在那兒一坐就是幾個(gè)小時(shí)，什么都不干。 4）表示猜測(cè)（可譯成"一定是、想必，等" ）This will be the house you're looking for .這想必就是你要找的房子吧。He will have gone back to New Zealand .他一定是回新西蘭去了。The person you mentioned would be the father , is that right ? 你說的那個(gè)人一定是爸爸了，對(duì)嗎？That would be in xx , I think .那大概是在xx年吧。5）will用于表示決心（可譯成"一定要,決心，等" ）We will never talk about that subject again .我們決不會(huì)再談?wù)撨@個(gè)話題了。I will make this puter work even if I have to stay up all night .我即使整晚不睡覺也一定要讓這臺(tái)計(jì)算機(jī)工作起來。6）would常用于虛擬條件句，表示與事實(shí)相反或不太可能實(shí)現(xiàn)的情況But for your help we would have been late .要不是你幫忙我們就遲到了。Well , I wouldn't worry about it . It won't do me any good .好了，我不會(huì)擔(dān)心那件事的，因?yàn)樗粫?huì)給我?guī)硎裁春锰帯?. 關(guān)于情態(tài)動(dòng)詞后面接進(jìn)行式和完成式的情況一般說來，"進(jìn)行式"表示動(dòng)作正在發(fā)生或進(jìn)行；"完成式"則表示動(dòng)作是發(fā)生在過去或是表示按理是發(fā)生了但事實(shí)上卻沒有發(fā)生。下面我們分別討論一下各種具體情況。A. 關(guān)于情態(tài)動(dòng)詞后面接進(jìn)行式的情況can后面接進(jìn)行式 表示可能正在發(fā)生的動(dòng)作，例如：What can she be doing at this moment ? 這個(gè)時(shí)候她會(huì)在做什么呢？You can't be telling us the truth.你不可能在對(duì)我將真話。Can he be still thinking of it I told him ? 他會(huì)不會(huì)還在考慮我告訴他的那件事呢？may后面接進(jìn)行式表示可能正在發(fā)生的動(dòng)作，例如：Your mother may be waiting for you to return home .你媽媽可能正等著你回家吧。She may be leaving for New York tomorrow or some day . 她或許明天或者什么時(shí)候會(huì)動(dòng)身去紐約。They may be returning back before Christmas .他可能圣誕節(jié)前回來。might后面接進(jìn)行式表示可能正在發(fā)生的動(dòng)作，例如：They might be planning to make a loan for their new project .他們也許在為他們的新項(xiàng)目策劃貸款的事。She might still be crying for being wronged .她或許因?yàn)槭芰嗽┩鬟€在啼哭。You might be telling me a lie .你也許在對(duì)我撒謊。must后面接進(jìn)行式 表示想必正在做某事，例如：You must be thinking where I learned it .你一定在想我是從哪兒知道這件事的。They must be following us just a little behind us .他們肯定在離我們不遠(yuǎn)的地方尾隨著我們。My brother must be sleeping in bed for it's so quiet in the house .家里這么安靜，我弟弟一定在床上睡覺。should后面接進(jìn)行式表示應(yīng)該正在做某事，例如：You should be doing your exercises instead of watching TV. 現(xiàn)在你該在做作業(yè)而不是看電視。You shouldn't be thinking about the solution only in one way .你不應(yīng)該只用一種方法考慮解決問題的辦法。Why should I be waiting here without doing anything ? 我憑什么在這兒白等。B.關(guān)于情態(tài)動(dòng)詞后面接完成式的情況can后面接完成式 表示可能已經(jīng)做了某事。例如：He can't have left home because the television is on .因?yàn)殡娨曔€開著所以他不會(huì)離開家了。Where can they have gone ? 他們會(huì)去了哪兒呢？You can't have finished the novel so soon .你不可能這么快就看完了那本小說。could后面接完成式 表示本可能發(fā)生或本可以做的事而沒有發(fā)生或沒有做；它的否定形式則表示本不可能發(fā)生或本不可以做的事而已經(jīng)發(fā)生或已經(jīng)做了。例如：The output could have been increased by 15% .產(chǎn)量本可以提高百分之十五的。How could he have forgotten him birthday ? 他怎么會(huì)忘了自己的生日呢？Judging from her appearance and manner,she couldn't have been over fifty years old . 從她的儀表和舉止來看，她不可能已有五十多歲了。may后面接完成式 表示可能已經(jīng)發(fā)生的動(dòng)作。例如：He may have had some training in Chinese Gongfu .他可能學(xué)過一些中國(guó)武術(shù)。You may have narrowly missed her on your way to here.你可能在來這兒的路上剛好與她錯(cuò)過了。They may have seen that movie.他們或許看過那部電影。might后面接完成式 表示本可能發(fā)生或本可以做的事而沒有發(fā)生或沒有做。例如：They might have finished their work by now .他們現(xiàn)在或許已經(jīng)完成任務(wù)。She might have done better than that .你本可以做得比這更好一些的。You might have learned more from him . 你本可以向他學(xué)到更多一些東西的。must后面接完成式 表示想必已經(jīng)發(fā)生的事。例如：You must have talked about it with her before hand .你一定事先與她談過這件事。It must have snowed last night for it's so cold this morning . 今天早晨這么冷，昨晚一定下雪了。ought to后面接完成式表示本應(yīng)該發(fā)生或本應(yīng)該做的事而沒有發(fā)生或沒有做；它的否定形式則表示本不應(yīng)該發(fā)生或本不應(yīng)該做的事而已經(jīng)發(fā)生或已經(jīng)做了。例如： They ought to have pleted their work much earlier .他們本應(yīng)該在更早一些的時(shí)候完成他們的工作的。You oughtn't to have left your keys in the office when you went out . 你不該出去的時(shí)候?qū)㈣€匙留在辦公室里。I ought to have said it to her in a calmer mood .我應(yīng)該以更平靜一些的語氣對(duì)她說那件事的。need后面接完成式主要用于否定句中，表示不必要做的事而已經(jīng)做了。例如：We needn't have read the Fast Reading materials before we do it in class . 我們?cè)谧隹焖匍喿x練習(xí)之前沒有必要把閱讀材料先看過了。You needn't have apologized to him for nothing yesterday .你昨天沒有必要無為地向他道歉.should后面接完成式表示本應(yīng)該發(fā)生或本應(yīng)該做的事而沒有發(fā)生或沒有做；它的否定形式則表示本不應(yīng)該發(fā)生或本不應(yīng)該做的事而已經(jīng)發(fā)生或已經(jīng)做了。例如：I should have written to you earlier. But I've really been busy .我本應(yīng)該早就給你寫信的；不過我真的一直都很忙。You shouldn't have left your son alone at home .你不該將你兒子一個(gè)人留在家里的。He shouldn't have broken the red light.他不該闖紅燈的。3. 常用情態(tài)動(dòng)詞的用法比較1）在表示"可能性"方面can 、should 、may 、might這四個(gè)詞都可以用來表示"可能性"。但在表達(dá)的語氣和程度方面有所不同：can 和should表示以事實(shí)、理由為依據(jù)而存在的可能性；其中should的主觀性較強(qiáng)，往往含有"應(yīng)該會(huì)怎么樣"的意思。總體上說，這兩個(gè)詞在這方面的語氣較強(qiáng)、較肯定。與之相比，may 和might這兩個(gè)詞在這方面的語氣較弱些、沒有那么肯定，表示主觀意斷的可能性，沒有足夠的客觀依據(jù)。其中，might的語氣更為委婉、更弱。例如：You can't expect to be a top student without working hard at your study .（這種可能性很大。因?yàn)椋慌W(xué)習(xí)怎么能成為尖子生呢？）This book should be found easily in the library .（說話人認(rèn)為，圖書館應(yīng)該有很多這類書籍，所以應(yīng)該很容易找到。）You may meet her at the party today.（說話人認(rèn)為，你今天或許有機(jī)會(huì)、有可能見到她。）You might mistake what I mean.（說話人婉轉(zhuǎn)地說明，大概、也許你誤會(huì)我的意思了。）2）在表示"允諾"方面在表示"允諾"的can ，may， might三個(gè)情態(tài)動(dòng)詞中，以might最為客氣、委婉；may為居中；而can是表達(dá)這方面意思的普通詞。在這種情況下，要根據(jù)具體情況來選用這三個(gè)情態(tài)動(dòng)詞。例如：You can leave now . （用于熟識(shí)的人之間；或是公事公辦的情況。）May I trouble you with a question ?（用于禮貌地提出請(qǐng)求。）Might I have another cup of coffee?（用于陌生或正式的場(chǎng)合，非常委婉、得體地提出請(qǐng)求。）3）在表示"應(yīng)該"方面must ，ought， should都能用來表示"出于某種職責(zé)、義務(wù)而應(yīng)該怎么樣"的意思。以must的語氣最強(qiáng)烈；ought為居中；而should是表達(dá)這方面意思的普通詞。例如：We must build our motherland into a strong country with four modernization .(語氣很強(qiáng)烈。表示我們應(yīng)該把自己的祖國(guó)建設(shè)成一個(gè)具有四個(gè)現(xiàn)代化的強(qiáng)國(guó)，而且我們非得這樣做不可。）我們一定要將我們的祖國(guó)建成為一個(gè)具有四個(gè)現(xiàn)代化的強(qiáng)國(guó)。Students ought to study hard .（這種用法較有針對(duì)性，較具體，作為學(xué)生要努力學(xué)習(xí)是責(zé)無旁貸的。學(xué)生應(yīng)當(dāng)努力學(xué)習(xí)。Students should study hard .（這種用法可理解為一般的提法、號(hào)召。）學(xué)生應(yīng)該努力學(xué)習(xí)。4）在表示"猜測(cè)"方面在情態(tài)動(dòng)詞中can 、should 、may 、might 、must都可以用于表示"猜測(cè)"。實(shí)際上， "猜測(cè)"與"可能性"在邏輯上是有必然聯(lián)系的。如果認(rèn)為沒有某種可能性，人們就不會(huì)作出某些猜測(cè)。因此，這里討論的五個(gè)情態(tài)動(dòng)詞之間的區(qū)別與他們各自在表示"可能性"方面的差異是相關(guān)的。- 在五個(gè)情態(tài)動(dòng)詞中must的語氣最為強(qiáng)烈，它是以事實(shí)為依據(jù)而進(jìn)行的邏輯上的推理，因此它所指的動(dòng)作發(fā)生的可能性最大。-can 和should表示以事實(shí)、理由為依據(jù)而進(jìn)行猜測(cè)，它們所指的動(dòng)作有發(fā)生的可能性，但語氣沒有must那么肯定。其中should的主觀性較強(qiáng)，往往表示說話人猜想"應(yīng)該會(huì)怎么樣"的意思。-may 和might這兩個(gè)詞在這方面的語氣較弱、沒有那么肯定，表示說話人根據(jù)自己的主觀意斷而進(jìn)行的猜測(cè)，一般地說沒有足夠的客觀依據(jù)。其中，might的語氣更弱一些。例如：As a football fan, he must have watched the football match on TV last night -Brazil vs. France .（說話人料定自己的推測(cè)不會(huì)有錯(cuò)：哪有足球迷不看巴西隊(duì)與法國(guó)隊(duì)比賽的道理。）作為一個(gè)足球迷，他昨晚肯定看了那場(chǎng)巴西對(duì)法國(guó)的比賽。He can't be out I just saw him a moment ago .（他不可能出去，因?yàn)槲覄倓傔€見過他。）他不可能出去，因?yàn)槲覄偛乓粫?huì)兒還見過他。It's 2:30 .I think she should be in her office .（現(xiàn)在兩點(diǎn)半是上班時(shí)間，她應(yīng)該在辦公室。）現(xiàn)在兩點(diǎn)半鐘。她應(yīng)該在她的辦公室。Brown may e back in ten minutes or so .（布朗或許一會(huì)兒回來，也許不回。）布朗或許十分鐘左右就會(huì)回來的。I thought although she was clever she might have difficultylearning a foreign language .（盡管她很聰明，但也許在學(xué)習(xí)語言方面會(huì)有困難。）我認(rèn)為，盡管她很聰明但也許在學(xué)習(xí)語言方面還是會(huì)有困難的。