河南专升本英语：语法复习专题六-情态动词、主谓一致

语法系列复习专题六-----情态动词、主谓一致

情态动词

一、一般疑问句中几个情态动词的问与答

1. Need I/he/…?

Yes,you/he/…must.(不用need)

2. Must I/ he/…?

No,you/ he/…needn’t/don’t(doesn’t,won’t)have to.(不用mustn’t)

3. May I/ he/…?

No,you/ he/…mustn’t.(少用may not)

4. Could(Can)you…?

Yes,I can (不用could)

5. Shall I/she/ he…?

No,you(she,he)needn’t/can’t/mustn’t

二、情态动词表“推测”

1.can,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.

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？

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。

三、“情态动词＋have done”用法

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./ 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.

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 st 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。

四、情态动词在反意疑问句中的用法

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?

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?

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

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