新人教必修3Unit1Festivalsaroundtheworld[情態(tài)動詞課件]

Modal verbs I 1. 情態(tài)動詞有一定的意義，只表示期待或估計(jì)某事的發(fā)生，不能表示正在發(fā)生或已經(jīng)發(fā)生的事情。 2. 沒有人稱和數(shù)的變化，即情態(tài)動詞第三人稱單數(shù)不加-s。 3. 不能獨(dú)立使用，它和后面的動詞構(gòu)成謂語。4. 情態(tài)動詞 除ought 和have 外，后面只能接不帶to 的不定式。5. 情態(tài)動詞沒有非謂語形式，即沒有不定式，分詞，等形式。 只作情態(tài)動詞的 can/could, may/might, ought to, must可情態(tài)可實(shí)義的 need, dare/dared可情態(tài)可助動詞的shall/should, will/would相當(dāng)于情態(tài)動詞的have to, used to情 態(tài) 動 詞 的 語 法 特 征 Must , can/could, may/might 的用法must1.must 表示推測時， 只能用于肯定句。must do 對一般時的肯定推測must have done 對過去發(fā)生的事情作出的肯定判斷must be doing/do 對現(xiàn)在的動作進(jìn)行肯定推測 他們買了一輛新車。 他們一定很有錢。They have bought a new car. They must have a lot of money.他現(xiàn)在一定在看小說。He must be reading novels now.路是濕的。昨天晚上一定下雨了。The road is wet. It must have rained last night. can/could 1. can /could 表示推測時，只能用在否定句或疑問句中。Its so late. Can Tom be reading?這個人不可能是瑪麗， 她生病了。這么晚了，湯姆還在看書嗎？It cant be Mary. She has fallen ill.can/could have done表對過去發(fā)生行為的可能性進(jìn)行推測“本可以，本來可能已經(jīng)”用于肯定句中剛才我還看見他了， 所以他不可能出國的。 I saw him just now so he couldnt have gone abroad.你本來可以考的更好。You could have had a better mark. may/might1.may/might表示推測時，只能用于陳述句，表示對現(xiàn)在或?qū)硪l(fā)生的動作把握不大。她們明天可能會到這里來。They may come here tomorrow. might 可用于指 過去的行為或者表示可能性更小。我問他我是否可以離開。I asked him if I might leave. （表過去）I asked him “May I leave now?”他也許在作功課吧。He might be doing his homework now. （可能性更小） 3.might/may have done,表示對過去發(fā)生的動作進(jìn)行可能性推測， 他可能去醫(yī)務(wù)室了。He may have gone to the clinic.他可能已經(jīng)從報紙上知道這個消息了。He might have read about the news in the newspaper. Will /Would you do? 表請求，表意志，愿望，決心would表過去反復(fù)發(fā)生得動作或某種傾向“總是,總要”used to表過去常常（現(xiàn)在已沒有這種習(xí)慣）“過去常常”used to 可與狀態(tài)動詞連用would不可以eg. He used to be a quiet boy. ()He would be a quiet boy. ( ) will/wouldIf you will help me with my English, I will be very happy. I promised that I would do my best. You shall do as I say. (命令)1.在陳述句中,shall用于二、三人稱表示允諾、警告、命令、決心等。Shall I open the window for you？（征求意見）2.在疑問句中,用于一、三人稱，用來表示請求或征求意見。shall ,should 和ought toTell him that he shall have the book tomorrow. (允諾)Nothing shall stop me doing it. (決心) Shall he fetch some water for you？（請求） Young people should learn how to use computers. 3. should常表示勸告、建議、命令，與ought to意義相近，但ought to多表示責(zé)任、義務(wù)，語氣強(qiáng)烈。Every citizen ought to obey law. You ought not to go.You should/ought to have told her the truth earlier. She shouldnt have left without saying a word.4.should/ought to have done表示責(zé)備或批評,意為“本應(yīng)該但”,ought to的語氣更強(qiáng)烈,用于否定則表示“本不該但”5.should用于可能性推測時,表“應(yīng)該，很可能”They left at 5:30. They should get there now. 1.-Excuse me, but I want to use your computer to type a report.-You _ have my computer if you dont take care of it.A. shant B. might not C. neednt D. shouldntA2. -When can I come for the photos ? I need them tomorrow afternoon. -They _be ready by 12 : 00 . A. can B. should C. might D. needB3. With so much work on hand, you _to see the game last night. A. mustnt go B. could have goneC. shouldnt go D. shouldnt have goneD - Need he start from the beginning? - Yes, he must. - No, he neednt/doesnt have to. 1.作情態(tài)動詞時,僅用于否定或疑問句,后接動詞原形,表“需要”need You neednt return the book now.2.neednt have done 表示做了本不必要做的事情,意為“本不必要”O(jiān)ur color TV set is still good enough. You neednt have bought a new one.3.need作實(shí)義動詞時,表示“需要”，有人稱、時態(tài)、和數(shù)的變化He needs to finish it this evening. The classroom needs cleaning. Students book P5 Help each other to solve some problems. Come up with what you cant solve by yourselves. DBXL Help each other to solve some problems. Come up with what you cant solve by yourselves. Homework1. Finish workbook exercises on page 42-43.2. DBXL P112.