英語(yǔ)情態(tài)動(dòng)詞講解

1、 情態(tài)動(dòng)詞Modal Verbs12021/8/6情態(tài)動(dòng)詞是什么？動(dòng)詞類別系動(dòng)詞情態(tài)動(dòng)詞助動(dòng)詞行為動(dòng)詞能獨(dú)立做謂語(yǔ)不能獨(dú)立做謂語(yǔ)22021/8/6情態(tài)動(dòng)詞是什么？n必須要和其他動(dòng)詞連用；n可表示說(shuō)話人的語(yǔ)氣，用來(lái)表達(dá)建議、要求、可能和意愿等；n沒(méi)有人稱和數(shù)的變化。32021/8/6常用情態(tài)動(dòng)詞n現(xiàn)在式 can 過(guò)去式 could （能，可能）n現(xiàn)在式 may 過(guò)去式 might （可以）n現(xiàn)在式 shall 過(guò)去式 should （應(yīng)該）n現(xiàn)在式 will 過(guò)去式 would （會(huì)，將要）nmust 無(wú)時(shí)態(tài)之分nhad better、 dare、 need、 ought to42021/8/6

2、情態(tài)動(dòng)詞can/could1. can表現(xiàn)在的能力 I can swim , but my sister cant.2. could表過(guò)去的能力 At that time we thought the story could not be true.3. You cannot smoke in the meeting room. (此句的cannot 表示“禁止”) 52021/8/6情態(tài)動(dòng)詞can/could3. can/could 與be able to 相比be able to 可用于各種時(shí)態(tài)，表能力，強(qiáng)調(diào)成功地做某事was/were able to: 設(shè)法做成某事 相當(dāng)于managed

3、 to do sth suceeded in doing sth62021/8/6情態(tài)動(dòng)詞may/might1.may表示請(qǐng)求別人允許e.g. May I use your bike?2.may/might表示可能性e.g. He may be a teacher.3. may用于表示,應(yīng)該(多用于法律條文）e.g. Payment may be paid by check. 72021/8/6情態(tài)動(dòng)詞shall/should1. 用于第一、三人稱，征求對(duì)方意見(jiàn) e.g. Shall we go now? What should we do next ? (用should 比 shall 表示

4、更客氣)2.shall 用于法律、規(guī)定，表示義務(wù)和規(guī)定8.g. The sign reads:No person shall smoke here!3.should表示應(yīng)該 e.g. You should not judge a man by his clothes.82021/8/6情態(tài)動(dòng)詞 will/would1. 用于向第二人稱征求對(duì)方意見(jiàn)(would 比 will 更客氣)e.g. Would you please open the door?2. will表示個(gè)人主觀意愿e.g. I will help you anytime.3. would“表過(guò)去常?！眅.g. When he

5、was there, he would go to that coffee shop every day.注：used to do “過(guò)去常常，強(qiáng)調(diào)現(xiàn)在不了”92021/8/6情態(tài)動(dòng)詞 must1. must 表必須e.g.You must keep the place clean. (務(wù)必) mustnt 禁止e.g. When I was young, I was told that I mustnt play with fire.2.must 還可表示“偏偏，偏要”e.g. Must you make so much noise?102021/8/6情態(tài)動(dòng)詞 must /have to1

6、. must 表示主觀意愿，否定句用mustnt，否定回答用neednte.g. You mustnt play in the street.Must I clean the room now?No,you neednt.2. have to表示客觀條件的限制的“不得不”，它有時(shí)態(tài)和人稱變化，需要助動(dòng)詞來(lái)否定和疑問(wèn)。e.g. I dont have to carry the big box. He had to wash his clothes.112021/8/6情態(tài)動(dòng)詞表推測(cè)可能性的強(qiáng)弱層次must should/ought to can/could may/might1. should/

7、ought to表示推測(cè)根據(jù)經(jīng)驗(yàn)的推測(cè)，“應(yīng)當(dāng)、應(yīng)該”e.g. Your photos should be ready by12:00.表示“竟然”，帶有感情色彩e.g. It is incredible that you should like him.122021/8/6can/could 表推測(cè)1.常用于否定句和疑問(wèn)句 e.g. He cant be at home. (否定句) Can the news be true ? (疑問(wèn)句)2. can 用于肯定句中表示理論上的可能性，并不涉及是否真的會(huì)發(fā)生e.g.You can hurt yourself if you play in the street.132021/8/6 may/might表推測(cè)1.may well”極有可能”e.g. Liza may well not want to go on the trip,because she dislikes travelling.2.may/might as well”不妨”e.g. You may as well try to do it.142021/8/6can? may? must? could? might ?1. Jim _can_ sing very well.2. Hello, _may/m