【正文】 e suitable person than him for the job can not be 。Such kind of thing can39。t be so stupid to do 。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。m afraid that we couldn39。You could have done better if you had worked harder at ，本來可以干得更好一些的。只有情態(tài)動(dòng)詞ought要和帶to的動(dòng)詞不定式連用，在句中作謂語用。但是can只能有現(xiàn)在式和過去式，而be able to則有更多的形式，如：He will be able to do the work “經(jīng)過努力才得以做成功某事”時(shí)應(yīng)用be able to，不能用Can。If that is the case, we may as well 、祈求、祝愿，常可譯為祝愿。如：May I use this dictionary?Yes, ，如果Might I…? 就比用May I…? 語氣更婉轉(zhuǎn)些，如：May I have a look at your new puter? 但是表示“阻止”或“禁止”對(duì)方做某事時(shí)，要用must not代替may not，如：May we swim in this lake?No, you mustn’’s too dangerous.(2)may或 might都可以表示可能性，表示“或許”、“可能”之意，如果用might表示可能性，則語氣更加不肯定，如：They may(might)be in the library 、must的基本用法(1)must表示“必須”、“應(yīng)該”之意，其否定式 must not，縮寫形式為 mustn39。t(doesn39。t(don39。s too could have answered it earlier, I am sure.(2)may, might后接完成式的用法①表示對(duì)過去某事的推測(cè)，認(rèn)為某一件事情在過去可能發(fā)生了。t 或是don39。No , you needn39。例如：You ought to have helped him.(but you didn’t)這時(shí)，ought與 should可以互相換用。(3)needn39。你還要告訴其他學(xué)生要帶筆，還有他們不能遲到。他竟然是我最喜愛的演員。竟然They should be home by 、will的基本用法(1)表意愿，用于各人稱陳述句，可以表示“意志”或“決心”，如：I have told him again and again to stop smoking, but he will not you will read the book, I will lend it to you.(2)在疑問句中用于第二人稱，表示說話人向?qū)Ψ教岢稣?qǐng)求或詢問對(duì)方的意愿，如：Will you please tell me how to get to the Capital Gymnasium?(3)will表示某種傾向或習(xí)慣性動(dòng)作，可以表示一種習(xí)慣性的動(dòng)作，有“總是”或“會(huì)要”之意 Fish will die out of door won’t ?！癢hatever you want you shall have , ”said the ：“你想得到什么，你就可以有什么。t be ，她不會(huì)太受壓的。He shall not e into my 。This law shall e into effect on January 1st 2001 這個(gè)法律于2001年元月1日生效。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。You should write to your parents at least once a 。t be out in such an early 。3）表示驚訝、失望等情緒I think it is dreadful that anyone should be so ，竟然每個(gè)人都如此傷心就太糟糕了。4）用于某些從句中表示虛擬語氣The doctor insisted that the girl should be 。I39。）I was shocked that she should have said such a thing to you.（她竟然對(duì)你說這種話，真讓我吃驚。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？Won39。t let the doctor take his blood 。He would sit there for hours, doing nothing at ，什么都不干。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 1999 , I 。Well, I wouldn39。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。It must have rained last night for it is so wet ，昨晚肯定下雨了。We can be there on time 。He must have been 。We can39。t help ，我?guī)筒簧夏?。With the teacher?s help, I shall be able to speak English , 我將能準(zhǔn)確地講英語。He said he might lend us some 。Might I borrow some money now? 我可以借點(diǎn)錢嗎? He might be 。You mustn39。He had to go because of somebody?s calling him that ，因?yàn)橛腥私兴?。It39。You must do it 。 “需要”， I att。(客觀條件必須現(xiàn)在走)You must be here on time next 。clock already, we must have been late ，我們一定又遲到了。He must have told my parents about 。Must I return the book tomorrow? 我必須明天還書嗎?After such a long walk, you must be , 你一定累了。must 用來指一般現(xiàn)在時(shí)和一般將來時(shí)，過去式可用 have to 的過去式代替。might 是may 的過去式，有兩種用法，一種表示過去式，一種表示虛擬語氣，使語氣更加委婉、客氣或?qū)赡苄缘膽岩伞ou may take the book 。Can you pass me the books? 你能給我遞一下書嗎 ? Could you help me, please? 請(qǐng)問, 你能幫助我嗎? What can you do? 你能干點(diǎn)什么呢? Can you be sure? 你有把握嗎?can 和could 只能用于現(xiàn)在式和過去式兩種時(shí)態(tài)，將來時(shí)態(tài)用be able to 來表示。I39。個(gè)別情態(tài)動(dòng)詞有現(xiàn)在式和過去式兩種形式，過去式可以用來表達(dá)更加客氣、委婉的語氣，時(shí)態(tài)性不強(qiáng)，可用于過去，現(xiàn)在或?qū)怼Ｇ閼B(tài)動(dòng)詞數(shù)量不多，但用途廣泛，主要有下列： can(could), may(might), must, need, ought to, dare(dared), shall(should), will(would).二、情態(tài)動(dòng)詞的位置情態(tài)動(dòng)詞在句中放在謂語動(dòng)詞之前，謂語動(dòng)詞前若有助動(dòng)詞，則在助動(dòng)詞之前，疑問句中，情態(tài)動(dòng)詞放在主語之前。t see you in class must have been ，你肯定沒有來。It must be that naughty boy crying 。t do me any ，我不會(huì)擔(dān)心那件事的，因?yàn)樗粫?huì)給我?guī)硎裁春锰?。I will make this puter work even if I have to stay up all 。re looking 。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 ，那只貓總是整個(gè)下午都躺在那兒。I will pay you at the rate you 。當(dāng)然will 和would又都有一些各自不同的獨(dú)特用法。Take an umbrella with you in case it should ，以防萬一下雨。s care the girl should not be speaking to you ，這個(gè)女孩現(xiàn)在就不能與你說話了。It39。The event should lead them to a even worse economic 。They should do it for their own 。）1）表示出于職責(zé)、義務(wù)該做某事You shouldn39。The renter shall keep the house in a neat and orderly 。3）決心（表示某事一定會(huì)發(fā)生）That day shall 。2）命令You shall e to my office 。t want to be hard on your daughter。Every time she was in trouble, she would go to him for 用作情態(tài)動(dòng)詞時(shí),適用于第二人稱和第三人稱。(1)should作為情態(tài)動(dòng)詞可以表示“建議”或“勸告”，有“應(yīng)該”之意，如：You should learn from each other.(2)should后接完成式表示過去沒有做到本來應(yīng)該做的事情，或是做了本來不應(yīng)該做的事情。Stay at home in case he should e to visit 。用于第二，三人稱的陳述句是表示說話人(并非主語)的意志或愿意，含命令，許諾，威脅等含義。例如：Ought you smoke so much? You oughtn’t smoke so 、dare的基本用法(l)dare(dared為其過去式)作情態(tài)動(dòng)詞用時(shí)，主要用于否定句，疑問句和條件從句中，如：Dared he bread the traffic regulations again?(2)在現(xiàn)代英語中dare常用作行為動(dòng)詞，其變化與一般行為動(dòng)詞相同，如：She dares to stay at home alone at 、need的基本用法(1)need作情態(tài)動(dòng)詞用時(shí)，主要用于否定句和疑問句中，如：He needn39。t have to).不，不必今天交。t意思是“絕不能、一定不要”，而沒有“不必”的意思。t do the work well that might have done it better.(3)must后接完成式的用法：表示對(duì)過去某事的推測(cè)，認(rèn)為某事在過去一定做到了，如：Liu Dong isn’t in the must have gone to the 、have to 的基本用法：have to和must的意義相近，只是 must側(cè)重表示說話人的主觀看法，而have to 則表示客觀需要注意：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mustn39。 know his father has just bought him a new 、can, could, may, must后接完成式的用法(1)can, could后接完成式的用法：①在否定句或疑問句中表示對(duì)過去發(fā)生過的事情的“懷疑”或“不肯定”的態(tài)度，Could he have said so? ②在肯定句中，可以表示過去可能做到而實(shí)際并沒做到的事情，有“勸告”或“責(zé)備”的語氣。t，因?yàn)閙ustn39。t touch the fire.(2)對(duì)以must提出的疑問句，如作否定回答時(shí)，要用needn39。May you be happy！祝你幸福！(1)表示允許或征詢對(duì)方許可，有“可以”之意，如：You may use my “可以做某事”或“不可以做某事”時(shí)，一般多不用may或 may not，以避免語氣生硬或不容氣。當(dāng)然may 和might又都有一些各自不同的獨(dú)特用法。現(xiàn)將各情態(tài)動(dòng)詞的基本用法分述如下：can和could(could為can的過去式)的基本用法(1)表示能力，如：He can speak English better than you.(2)在疑問句和否定句中表示“懷疑”、“猜測(cè)”或“可能性”，如：Can this green bike be Liu Dong39。情態(tài)動(dòng)詞沒有人稱和數(shù)的變化。I could e earlier if ，我可以來早一點(diǎn)。而是could自己獨(dú)特的用法。t / can39。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)徫业氖韬觯袉幔?）（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 couldn39。When the storm stopped , the plane could take ，飛機(jī)可以起飛