4.含有must句子的反意问句

　　 1)must表示“必须”时，附加部分常用needn’t,也可用mustn’t.例如：He must go with you,needn’t/mustn’t he?

　　 2)mustn’t表“一定不能”时，附加部分用may.例如：She mustn’t leave,may she?

　　 3)must表“一定、想必”推测意时，附加部分主要有下列几种形式：

　　 A.He must be an engineer,isn’t he?They must be writing now,aren’t they?(这类句子问句前部分含“must be…”或“must be doing…”。)

　　 B.She must have a car/live there, doesn’t she?

　　 C.He must have seen the film,hasn’t he？(这类句子问句前部分的谓语为must have done,句子无具体过去时间状语。)

　　 D.He must have seen the film last week,didn’t he?(这类句子问句前面部分的谓语为must have done,句子有具体过去时间状语。)

　　 E.Mother must have been shopping then,wasn’t she?(前面部分谓语为must have been doing。)

3.Let’s…,shall we? ; Let us…,will/won’t you?

2.“否定祈使句+附加问句”结构，附加问句常用will/would you形式。

　　 例如：Don’t watch TV,will/would you?

1.“肯定祈使句+附加问句”结构，附加问句常用will/would/won’t you形式。

　　 例如：Stand still,will/would/won’t you?

3.might have done,意“过去可能做”；could have done意“本能够做”，两者都含有委婉批评或遗憾之意，也可表对过去情况的推测。

　　 例如：He might have gone to Nanjing with Professor Wang.last week,but he was ill.上星期他本可以和王教授一起去南京的，可他病了。We could have finished the work ahead of time.我们本来是能够提前完成工作的。

2.shouldn’t/oughtn’t to+have done,意“本不应该”，含有责备或后悔意。

　　 例如：You shouldn’t have watered the flower./I oughtn’t to have scolded her for such a small thing.

1.should/ought to +have done,意“本应该…”，含有责备或后悔意。

　　 例如：You should have come here a little earlier./I ought to have sent him to school./

4.对已发生的事情进行推测：

　　 句式：must/may/might/can/could+have done

　　 例如：There’s no lignt in the room. They must have gone to bed./She knows nothing about the film. She can’t/couldn’t have seen it./Can/Could he have been a doctor?/He may/might(not)have been a teacher./They must have been watching TV at nine last night./Can/Could she have stayed in Beijing last year?

　　 注意：will have done句式也可表“肯定/可能已经…”推测意。

　　 例如：He will have learned advanced mathematics,for he knows a lot about it. 他肯定/可能学过高等数学，因为他对此懂得很多。

3.对目前正在发生的事情进行推测：

　　 句式：must/may/might/can/could+be doing

　　 例如：They must be waiting for us.他们肯定正在等我们。

　　 She may/might be doing her homework.她可能正在做作业。

　　 Can/Could he be playing football?他会正在踢足球吗？

　　,may,must使用的句式：

　　 1)肯定陈述句中：must表“肯定、必定、一定”意，may/might表“也许，或许”意。

　　 2)否定陈述句中：can’t/couldn’t表“不可能”意，may not/might not表“也许不、可能不”意。

　　 3)疑问句中：只能用can或could,不能用must,may或might。

　　 注意：表推测的could,might并不是指过去时间，而是表示比can,may把握性略小些的情况。

2.对目前状态的推测：

　　 1)must/may/might/can/could+be+表语

　　 例如：She must be a teacher.她肯定是老师。She can’t/couldn’t be a doctor.她肯定不是医生。 He may not/might not be a doctor.他可能不是医生。

　　 2)must/may/might/can/could+一些不能用于进行时的静态动词(如:have,exist,live,like,hate,own,belong to等)

　　 例如：She must have her own car,for she has a lot of money.

　　 That kind of bird may live in the valleys.