【2020年高考必備】高考英語第一輪復(fù)習(xí)(語法)——情態(tài)動(dòng)詞

1、咼考英語第一輪復(fù)習(xí)（語法）情態(tài)動(dòng)詞1、情態(tài)動(dòng)詞的基本用法（1）can、be able to 和 could1can 和 be able to 都表示能力，意思上沒多大區(qū)別。但can 只有現(xiàn)在和過去時(shí)，而 be able to 則有更多的形式。但當(dāng)成功地完成某一具體動(dòng)作時(shí)，通常不用 could 而用 was/were able to 來表示。這時(shí) was/were able to 相當(dāng)于 man aged to，表示經(jīng)過一番努力，終于能夠完成某事。如：Can you use chopsticks?The wounded man still was able to get to the villa

2、ge and was saved in the end.2can 和 couldcan 和 could 都可以表示能力、技能、許可、建議或請求和可能性。但比較委婉 客氣地提出問題或陳述看法，一般用could，回答時(shí)則用 can。如：Could you help me carry the bag?Can I help you?（2）may/might1may/might 表示可能，但 may 比 might 可能性大。女如: -Whyisn t he in class?He may be sick.（ 生病的可能性較大） He might be sick.（ 生病的可能性較?。?may/migh

3、t 表示“允許”，may 用于現(xiàn)在時(shí)或?qū)頃r(shí)，might 常用在間接引語中 表過去時(shí)， 但 might 也可用于現(xiàn)在時(shí)間， 表示比較委婉的語氣， 回答用 may。 如：He sayswe may leave.He said we might leave.3may / might 表示建議或請求，但 might 比 may 更客氣，意思更肯定而無過去時(shí)態(tài)的含義。Yes, you can / may.May / Might I use your bike? No, you mustnt(3)must1must 表示必須，應(yīng)該，沒有時(shí)態(tài)變化。如：You must do everythi ng as

4、I do.2must 表示肯定的推測。如：The light is still on, so he must be at home.3mustn t 表示禁止做某事。如：You mustn t smoke in the office.（4） have tohave to 表示“必須、不得不”，是由于某種外界（客觀）原因而“必須”，“不 得不”做某事，也可表示經(jīng)常的或習(xí)慣性的事“必須”做。 have to 的否定形式 表示不必。have to 可用于多種時(shí)態(tài)中。如：You will have to clea n your own boots whe n you join the army.I h

5、ave to be at my office every eve ning.（5） should / ought to1should 和 ought to 表示應(yīng)當(dāng)、應(yīng)該，前者比后者語氣輕。如：You should / ought to work hard.2should / ought to work hard.Since she is not here, whe should / ought to be in the classroom.3should / ought to的否定形式表示禁止之意。如：Children shouldn t smoke.4should 可表示陳述意見，推出建議

6、或請求；而 ought to 可以表示勸告之意。如：You ought to respect your pare nts.He suggested that they should leave at on ce.（6） will / would1will 用于各種人稱表示“意志”、“意愿”或“決心”等，否定式 won t +動(dòng) 詞。如：I will tell you all about it.Tom won t do such a thing.2will 用于疑問句中，常用在第二稱時(shí)表示說話人向?qū)Ψ教岢觥罢埱蟆被颉霸儐枴比纾篧ill you please tell her the n ews

7、whe n you see her?3will 表示習(xí)慣性的動(dòng)作，有“總是”、“慣于”的含義。如：Fish will die out of water.4would 表示客氣的請求、建議或意愿。如：Would you please be quiet?Would you like coffee?5would 表示過去反復(fù)發(fā)生的動(dòng)作。如：Whenl passed my school I would see my teachers who taught me5 years ago.（7） needneed 作“必要”講，既可作情態(tài)動(dòng)詞，也可作實(shí)義動(dòng)詞。作實(shí)義動(dòng)詞時(shí)后面的 動(dòng)詞不定式要帶 to，其變化

8、與一般動(dòng)詞相同。如：I need to think it over.Need you go now? Yes, I must./No, I needn t（8） daredare 表示“敢”的意思。作為情態(tài)動(dòng)詞時(shí)，主要用在疑問句和否定句中。dare若作實(shí)義動(dòng)詞，后面可帶 to 的不定式，此時(shí) to 也可以省略。dare 與 need 的用 法相似。如：How dare you say that?She doesn t date（to）ask her father.（9） used toused to 表示過去常常發(fā)生的動(dòng)作或存在的習(xí)慣，但現(xiàn)在已不復(fù)存在了。如：He used to smoke.

9、（10） shall1shall 作為情態(tài)動(dòng)詞用于第二、三人稱，表示說話人的意愿，有“命令” 、“警 告、威脅、強(qiáng)制”和“允許”等意思。如：We shall do as our teacher says.You shall have the book as soon as I finish it.2在疑問句中，shall 用于征求對方的意見或請求指示，常用于第一、第三人稱。 如：Where shall he wait for us?Shall we go out for a walk?2、情態(tài)動(dòng)詞表示推測或判斷的用法 下表即是表示推測的情態(tài)動(dòng)詞使用的場合: 情態(tài)動(dòng)詞對現(xiàn)在和未來的推測 對過去的

10、推測使用場合must must + 動(dòng)詞原形 must have done 肯定句may / might may / might +動(dòng)詞原形 May / might have done 肯定句、否定句can /could can / could do Can / could have done否定句、疑問名(could可用于肯定句)should 用來表示一種估計(jì)的情況“按理會(huì) /估計(jì)會(huì)” should do/be should have done肯定句、否定句、疑問句例如：It must have rained last ni ght.She may not be at home. = It

11、is possible that she is not at home.She can t be at home. = It is impossible that she is at home.They should be there right now.3、情態(tài)動(dòng)詞在虛擬語氣中的用法情態(tài)動(dòng)詞用于虛擬語氣中表示責(zé)備的感情色彩，用法如下：(1)should have done 表示“本來應(yīng)該做某事而實(shí)際上未做”， 而 shouldn t havedone 則表示“本不應(yīng)該做某事而實(shí)際上做了” 。如：You should have told me about it earlier.You shouldn t have said such words to your parents.(2)ought to have done也表示“本應(yīng)該”而 ought not tohave done則意為“本不應(yīng)該”。如：You ought to have told me about it earlier.You ought not to have said such words to your pare nts.(3) needn t ha