2017届高考英语二轮语法专题课件：专题6 情态动词_高考复习指南

2017届高考英语二轮语法专题课件：专题6 情态动词

　　我只好去。 ②You cannot be careful enough. 你再细心也不为过。 ③Her appearance has changed so much that you may well not recognize her. 她的模样变化太大，你很可能认不出她了。 ④You may as well do it at once. 你最好马上就做这件事。三、5大表示推测的情态动词用法比较情态动词适用句式适用时态意　义典句例示 must 肯定句一般时、进行时、完成时一定、肯定 ①You must be hungry after the long walk.

　　②He must be sleeping in the dormitory. can(could) 疑问句，否定句一般时、进行时、完成时可能，能够 ①She can't be reading in the reading room now.

　　②Can/Could this be an excuse for that？ may(might) 肯定句，否定句一般时、进行时、完成时也许，可能 ①He may not be happy.

　　②He may be playing basketball on the playground. should(ought to) 肯定句一般时确定或期待，“应该” ①He should be around sixty years old.(确定) ②It's nearly seven o'clock.Jack should be here at the moment.(期待) will(would) 肯定句、否定句、疑问句一般时、进行时、完成时大概 ①He will have forgotten me.I left him 18 years ago.

　　②It would be about ten when he left home. 四、“情态动词＋have done”用法类型构成用法句式典句例示对过去的推测 must have done 表示对过去已经发生的行为进行推测，意为“想必/准是/一定做了某事”。肯定 You must have gone to bed late last night.Your eyes are red. can/could have done 表示对过去发生的行为的怀疑和不肯定否定、疑问 He cannot have forgotten it. may/might have done 表示对过去已发生的行为的推测，意为“也许/或许/已经(没有)……”。肯定、否定 It's too late.I think he may have gone to bed. 类型构成用法句式典句例示表示后悔、责备或遗憾 could have done 表示过去没有实现的可能性，意为“本来可以……” 肯定 The accident could have been avoided. should/ought to have done 表示本该做某事而实际上未做肯定、否定 You are late.You ought to have arrived five minutes earlier. needn't have done 表示做了本来不必做的事否定 I actually needn't have bought so much wine—only three people came. had better have done 用于事后的建议，含轻微责备的口吻，意为“当时最好做了某事” 肯定、否定 You had better have started earlier. would rather have done 表示“当时宁愿做了某事” 肯定、否定 I would rather have taken his advice. 1．情态动词不能单独作谓语，必须与其它动词一起作谓语。另外，(1)后面接动词原形。(2)没有人称和数的变化。(3)变为疑问句或否定句时不需要加助动词，而是将情态动词移至主语前变为疑问句，在情态动词后加not，构成否定句。 2．掌握一些有关情态动词的常用句型，在语法填空题中极易考查到。如：cannot...too无论怎样……也不过分，You cannot be too careful while driving.开车时你越小心越好。