【正文】 情態(tài)動(dòng)詞主要用來(lái)表示說(shuō)話人的情感、態(tài)度等，是中學(xué)英語(yǔ)語(yǔ)法的重點(diǎn)，也是高考的熱點(diǎn)，是單項(xiàng)填空必考的一個(gè)知識(shí)點(diǎn)。情態(tài)動(dòng)詞在近五年高考中主要考查四點(diǎn)：情態(tài)動(dòng)詞表示推測(cè)和可能性的用法；情態(tài)動(dòng)詞與虛擬語(yǔ)氣；情態(tài)動(dòng)詞表達(dá)“情感、態(tài)度、語(yǔ)氣等”；情態(tài)動(dòng)詞表示 “必要性”等方面的用法。虛擬語(yǔ)氣的考點(diǎn)主要集中在名詞性從句、條件句中的用法，以及錯(cuò)綜條件句中虛擬語(yǔ)氣的應(yīng)用。 概念1. 什么是情態(tài)動(dòng)詞?本身有一定詞義，是表達(dá)說(shuō)話人的情感、態(tài)度、語(yǔ)氣的詞，其作用是給動(dòng)詞增添感情色彩?表現(xiàn)形式：情態(tài)動(dòng)詞+動(dòng)詞原形/be2. 特點(diǎn)?沒(méi)有人稱和數(shù)的變化?不能直接跟賓語(yǔ)，必須搭配實(shí)義動(dòng)詞或be動(dòng)詞的原形?情態(tài)動(dòng)詞的過(guò)去式往往不表時(shí)態(tài)，而表示更加委婉的語(yǔ)氣。例句：Can/could you help me?2. 情態(tài)動(dòng)詞的表現(xiàn)形式1） 情態(tài)動(dòng)詞+do 例句：We must help each other to overe the difficulties. You shouldn’t be so careless.2） 情態(tài)動(dòng)詞+be doing 例句：She must be sleeping now. My mother may/might be cooking now3） 情態(tài)動(dòng)詞+be done 例句：Difficulties can and must be overe. Something must be done to stop pollution.4） 情態(tài)動(dòng)詞+have done 例句：You ought to have e earlier. They might have finished the work. 情態(tài)動(dòng)詞的分類1. 只能作情態(tài)動(dòng)詞：must, can/could, may/might2. 可作情態(tài)動(dòng)詞也可作助動(dòng)詞的：will/would, shall/should3. 可作情態(tài)動(dòng)詞有可作實(shí)義動(dòng)詞的：need， dare4. 具有情態(tài)動(dòng)詞特征的：ought to, have to, be able to 分類講解 /could 1)表示能力：會(huì)，在表示過(guò)去的能力時(shí)用could 例句：I can swim. Lucy can dance well and her mother could dance well when she was young. The cinema can seat 500 people. I could not read such an easy book when I was 7 years old.2) 表允許，許可常用在口語(yǔ)中，此時(shí)could 不表示過(guò)去式，而表示語(yǔ)氣上比can更客氣。例句：Could I use your dictionary? Yes,go ahead./Yes, you can.(不可以說(shuō)Yes, you could.) He asked me whether he could take the book out of the reading room.一、 情態(tài)動(dòng)詞表推測(cè)的用法 情態(tài)動(dòng)詞 意義 語(yǔ)氣 句式 語(yǔ)境 例句 備注 must一定 可能性最大 肯定句 對(duì)具體事實(shí)的判斷①A：Look，someone is ing. Who can it be? B: It may be our headmaster. A: It can’t be him. He has gone to Shanghai. B: It must be Mr. Wang. He looks like our headmaster. ②That may not be true. ③He couldn39。t have discovered the truth. ①對(duì)現(xiàn)在的行為或狀態(tài)的推測(cè)：must/may/might/can/could＋do ②對(duì)過(guò)去的行為或狀態(tài)的推測(cè)：must/may/might/can/could have done may/might(might可能性小于may)可能可能性較小，尤其might最不肯定肯定句、否定句(可能不)can/could (could可能性小于can)可能疑問(wèn)句、否定句(不可能)、(could有時(shí)也用于肯定句)有時(shí)會(huì)肯定句情態(tài)動(dòng)詞 意義 語(yǔ)氣 句式 語(yǔ)境 例句 備注 should /ought to應(yīng)該 ，理應(yīng) 理論上①It39。s 8 o39。clock now. He should be in the office now. ②Hi, Mum! I39。m on the bus. I should be home in about ten minutes. 常表示在一段時(shí)間內(nèi)可能發(fā)生的事或某人的期望。一般句末有時(shí)間狀語(yǔ)，或有語(yǔ)境暗示。所表示的猜測(cè)發(fā)生的可能性很大。 注意：should (ought to)表示推測(cè)是高考考查的重點(diǎn)和難點(diǎn)。如：— When can I e for the photos？I need them tomorrow afternoon.— They ________ be ready by 12：00. A．can B．should C．might D．need 【解析】 B　A項(xiàng)表示推測(cè)時(shí)常用于否定句和疑問(wèn)句中。C項(xiàng)表示推測(cè)語(yǔ)氣不太肯定。should意為“按理說(shuō)，理應(yīng)”，既回答了顧客的詢問(wèn)，不失禮貌，又為照片有可能尚未洗好，顧客到時(shí)取不到留下了回旋的余地，體現(xiàn)了店主的精明與用詞經(jīng)過(guò)仔細(xì)推敲。 二、情態(tài)動(dòng)詞的其他用法1．can, could, may, might情態(tài)動(dòng)詞意義 例句 備注 can/could能力 ①I can see some birds flying in the sky. ②Could the girl read before she went to school? could表示泛指過(guò)去的某一能力。表示過(guò)去有能力并且成功地做了某事，通常用was/were able to do，相當(dāng)于managed to do/succeeded in doing。如：Because he practised hard, he was able to pass the driving test. 情態(tài)動(dòng)詞意義 例句 備注 can/could允許(有時(shí)可與may互換) Can/May I have a look at your photos？ can與could、may與might不表時(shí)態(tài)差異，只是語(yǔ)氣上的差別，could/might比can/may更委婉。注意在回答時(shí)不能用could/ might。 請(qǐng)求 —Can/Could you lend me a hand？—Yes, I can. 情態(tài)動(dòng)詞意義 例句 備注 may/might允許或請(qǐng)求 ①You may take this if you like.②May/Might I ask for a photo of your baby？ can與could、may與might不表時(shí)態(tài)差異，只是語(yǔ)氣上的差別，could/might比can/may更委婉。注意在回答時(shí)不能用could/ might。 , should 情態(tài)動(dòng)詞意義 例句 備注 must 必須 ①We must help each other to overe the difficulties. ②—Must I finish the work today？—No, you needn39。t/you don39。t have to./Yes, you must. ③You mustn39。t take photos here, and it is forbidden. ①must表示主觀意志，have to表示客觀。如：They had to speed up, for the weather turned terrible. ②Must I/we…？的否定回答不能用mustn39。t。 偏要硬要非要①Why must you always interrupt me？②—Can I borrow your car, Mum？—If you must. 表示與說(shuō)話人愿望相反及不耐煩。 情態(tài)動(dòng)詞意義 例句 備注 should 應(yīng)該(常與oughtto通用)You should be polite to the old. ought to 的否定式：ought not to(oughtn39。t to)；疑問(wèn)式：Ought …to…？ 竟然 It is strange that he should react in this way. 表示驚訝、意外等語(yǔ)氣。 萬(wàn)一 ①Should anyone phone, tell them I will call back later. (＝ If anyone should phone…)②If I should go there tomorrow, I would go to see her. 用于if從句中強(qiáng)調(diào)“萬(wàn)一”，或用于虛擬語(yǔ)氣。 3. need, dare 情態(tài)動(dòng)詞例句 注意事項(xiàng) need①I needn39。t go at once. ②—Need you go at once？—Yes，I must. /No, I needn39。t.①need可以作實(shí)義動(dòng)詞，用于各種句式。如：I need to go at don39。t need to go at once. —Do you need to go at once？—Yes，I do.②need作情態(tài)動(dòng)詞常用于否定、疑問(wèn)或條件句中。dare①He daren39。t cross the river.②How dare you say that to me？dare和need一樣，既可以作情態(tài)動(dòng)詞，也可用作實(shí)義動(dòng)詞。用作情態(tài)動(dòng)詞時(shí)，主要用于否定句、疑問(wèn)句和條件句。用作實(shí)義動(dòng)詞時(shí)，可用于各種句式。如：He didn39。t dare (to) go out alone at night. (在否定句中to有時(shí)可省略) 情態(tài)動(dòng)詞意義 例句 備注 shall 表示征詢意見(jiàn)。 Shall I help you？ 用于第一、第三人稱疑問(wèn)句中。 表示說(shuō)話人的意愿，有“命令，允諾，警告，決心”等意思。 ①You shall do as I say. (命令)②You shall have the book tomorrow. (允諾)③If you don39。t ge