情態(tài)動詞一can-may-must的用法

1、情態(tài)動詞can, may, must的用法,情態(tài)動詞后接動詞原形; 沒有人稱和數(shù)的變化; 不能單獨(dú)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not。,Modal verbs 情態(tài)動詞,can / can not may / may not must / must not,Modal verbs 情態(tài)動詞,can / can not,1. 表示能力(會) Mary can speak English, but she can not speak French. 2. 表示允許(可以) 也可用could (不是過去式)更委婉 Can /Could I use your dictio

2、nary? 3. 表示推測 (可能 ) -通常用于否定形式 He cant be in the office. I saw him go out just now.,1. S1 _ Kitty _? S2 _.,2. S1 _ Kitty _? S2 _.,Can spell,Yes, she can,Can add,No, she cant,may / may not,1. 表示允許(可以) 也可用might更委婉 May /Might I come in? 2. 表示推測 (可能) -通常用于肯定形式 She may be still waiting for us. 3. 表示祝愿 May

3、 you have a happy weekend.,may的用法:,may / may not,以may開頭的疑問句，其否定回答用cant或 mustnt。 -May I go home now? -Yes, you may. No, you cant/mustnt.,may not的用法:,Answers:,1. May I carry your bag for you? 2. May I open the door? 3. May I get you a chair? 4. May I switch on the TV? 5. May I borrow your new bicycle?

4、,must / must not,1. must表示必須 You must do your homework first. 2. must表示 “一定”(肯定性推測 ) 語氣較強(qiáng) He must be at home.,must的用法:,must / must not,1. mustnt表示禁止(不準(zhǔn)；不允許) You mustnt smoke here. 2. 以must開頭的疑問句，其否定回答要用neednt. - Must I clean the classroom now? - Yes, you must. No, you neednt.,must not的用法:,五.have to的

5、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,六need的用法,后加動詞原形 表示需要，必須，用于否定和疑問句 否定：neednt（不需要）， 疑問將need提前,注：用于肯定句時(shí)，常作實(shí)意動詞用：need to do sth,Need we return the magazines today？ yes， you must./

6、 no, you neednt.,You need not do this。,疑問句回答：同must,What do the signs mean? Do you know?,You must not cycle.,You must be careful.,You must turn left.,You must not enter.,You must pay ten yuan.,You must keep silent.,You must not turn right.,You must not smoke.,.用適當(dāng)?shù)那閼B(tài)動詞填空：。 1.I can play football. _you

7、 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?,Can,may,cant,must,must,Can,9. Nobody _live without air.

8、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