m3u1grammar情态动词

1、Justin Bieber 贾斯汀贾斯汀比伯比伯 Modal verbs情态动词情态动词1. can 与与could2. 表示推测，意为表示推测，意为“可能可能”“”“或许或许”，用于疑问句或否定句，用于疑问句或否定句1. 1.表能力表能力3. 表示表示“请求请求” “允许允许”(表请求时，口语中常用表请求时，口语中常用 could 代替代替 can 使语气更委婉，回答时用使语气更委婉，回答时用can)1) He can speak English.2) Some of us can use the computer now, but we couldnt last year.3) Can I

2、 believe you?4) The story cant be true.5) Can/Could I watch TV now?6) Could you lend me a hand?注意注意：can/could 和和 be able to 的区别的区别1. can强调本身具有的能力；强调本身具有的能力；be able to 强调经后天强调经后天努力而培养的能力努力而培养的能力,=succeed in doing sth 或或manage to do sth. 2. be able to 可用于任何时态；而可用于任何时态；而can 只有现在时和只有现在时和过去时过去时could。eg.

3、This time I failed in the exam, but Ill be able to pass the exam next time. Tom studied hard and was able to pass the exam.2. may 与与might1. 表示表示“许可许可”或或“请求请求”，might比比may 语气更委语气更委婉。婉。 否定回答时用否定回答时用“must not”表表“禁止，阻止禁止，阻止”，不，不用用 “may not”. Eg: 1)- May I watch TV after supper? - Yes, you may. / No, you

4、mustnt./you had better not. 2) Dont go alone. You might lose your way. 2. 表示推测。表示推测。 意为意为“或许，可能或许，可能” might 比比 may 可能性小。用于否定句，可能性小。用于否定句， “may not” 表示表示“可能可能不不” 。Eg: 3) You might be right. 4) They may be in the library now. 5) He may not know about the fact.3. May you +动词原形动词原形 表表“希望、祝愿、祈求希望、祝愿、祈求”

5、“祝你祝你”Eg: May you succeed.May you have a good trip.3. should1. 用于表劝告、建议。用于表劝告、建议。 意为意为“应该、应当应该、应当”。Eg: 1) You should keep your promise. 2) You should study hard.2. 用于表推测。用于表推测。 意为意为 “可能、应该可能、应该”Eg: 3) Its 7 oclock, he should be at home. 4) If the train is on time, she should arrive in Beijing by sev

6、en.3. 用于疑问或感叹句中，表示惊奇、赞叹、愤怒等情绪。用于疑问或感叹句中，表示惊奇、赞叹、愤怒等情绪。Eg: 5) What should I fear? 6) What should you do but crying for help?1在疑问句中与第一、三人称搭配，表在疑问句中与第一、三人称搭配，表“征询、征求征询、征求“意见意见”。Eg: 3)You shall get the book tomorrow. 4) He shall be punished. 5) You shall fail, if you dont work harder.允诺允诺警告警告4. shall2.

7、2. 在陈述句中与第二、三人称搭配，表示在陈述句中与第二、三人称搭配，表示“命令、命令、警告、威胁、许诺警告、威胁、许诺”。Eg. 1)What shall we do now? 2) Shall we go to movies?警告警告5. will与与would1.表示意志、意愿。用于陈述句中，表示意志、意愿。用于陈述句中，will指现在，指现在，would指过去。指过去。Eg: 1) I will marry you. 2) Ill help you , if you ask me. 3) I wont tell you anything. 4) I said I would do an

8、ything for you.2.表示请求、建议。用于第二人称的疑问句中，表示请求、建议。用于第二人称的疑问句中，would表更委婉的语气。表更委婉的语气。Eg: 5) Will you do me a favor? 6) Would you mind closing your mouth?3.表示过去习惯或反复发生的动作。（常与表示过去习惯或反复发生的动作。（常与used to作作对比）对比）Eg: 7) We would often find Li sleeping in the class. 8) When he was young, he would always stay up la

9、te. 9) He used to be very fat.(现无此习惯现无此习惯)6. must1. 表示表示 “必须必须”，否定形式，否定形式mustnt ( “不准不准”、“禁禁止止”)。Eg: 1) You must finish your homework first. 2) Children mustnt speak like that to their parents.2. 回答回答 must 所在的一般疑问句时，否定回答用所在的一般疑问句时，否定回答用 “neednt” 或或“dont have to”.Eg: 3)-Must we finish the work tomorr

10、ow? -No, you neednt/ dont have to, but you must finish it in three days.3. 表推测，用于肯定句，意为表推测，用于肯定句，意为“一定一定”、“务必务必”。Eg: 4) Betty must be in the next room. 5) He must know the truth. You _ buy a gift, but you can if you want to.must B. mustnt C. have to D. dont have to2. When I was young, I was told tha

11、t I _ play with fire. A. wouldnt B. neednt C. mustnt D. darent3. - May I smoke here ? - If you _, choose a seat in the smoking area. A. should B. could C. may D. must4. When he was there, he _ go to that coffee shop at the corner every day. A. would B. should C. had better D. might5. Whats the name

12、of the book? Khulaifi. _ I spell it for you? A. Shall B. Would C. Can D. Might6. That be Anns husband, for I am sure that he doesnt wear glasses.A. cant B. may not C. mustnt D. neednt 7. - Good morning. I got an appointment with Miss Smith yesterday. - Ah, you _ be Mr. Peter.A. might B. must C. would D. can8. What do you mean, there are only ten tickets? There _ be twelve.A. should B. would C. will D. shall9. It is usually war