1、一、情態動詞一、情態動詞can, may, mustcan, may, must的用法的用法 情態動詞后接動詞原形情態動詞后接動詞原形; 沒有人稱和數的變化沒有人稱和數的變化; 不能單獨作謂語不能單獨作謂語, 與后面的動詞共同作謂語與后面的動詞共同作謂語; 其否定形式在后面直接加其否定形式在后面直接加not。 can / can not may / may not must / must notModal verbs情態動詞情態動詞can / can not 1. Mary can speak English, but she can not speak French. (VS: be abl

2、e to ) 2. Can /Could I use your dictionary? 3.He cant /couldnt be in the office. I saw him go out just now.may / may not 1. May /Might I come in? 2.She may/might be still waiting for us.must/ must not 1.You must finish your homework first. (VS: have to ) 2.He must be American.表示推測、可能性，表示推測、可能性，must

3、can could may mightneed / need not1.We need to have a rest .2.-Need I clean my classroom now? -No, you neednt. (VS: dont have to )may/must/need 的一般疑問句及其回答：的一般疑問句及其回答：1. May I.? Yes, you can. / Yes, you must. No, you cant.2. Must I .? Yes, you must. / No, you neednt.3. Need I .? Yes, you must. / No,

4、you neednt.二.have to的用法 表示客觀需要 “不得不，必須”I missed the train, so I had to take a taxi. 在疑問句和否定句中，have to需借助助動詞 do ， Did he have to do it? You dont have to go there. （不必，不需要） neednt考慮：have to 與 must的區別三、had better 的用法 表示 “最好.”Youd better get some sleep. had better + （not）do sth. nik.用適當的情態動詞填空：。1.I can

5、play football. _you swim?2.Dont worry. You _ return me this book tomorrow.3.My grandma is ill. You _ talk so loudly here .4.I cant play with you. I _finish my homework first.5.I_ get up early tomorrow. because I have a meeting.6._you please open the window? CanmaycantmustmustCan9. Nobody _live witho

6、ut air.10._he speak Chinese ?Yes ,a little.11. The book _ be returned before Saturday.12._I come in ?Yes ,please.13. You _give up smoking at once. Its bad for your health.14. Excuse me ._I ask you a question?15. _you tell me where the station is ?16. _ I finish the work now ?No, you _. You _ do it this evening.17. May I use your dictionary ? Sorry , you _. I am using it now .18. Look at the ground