情态动词、主谓一致.doc

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。 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