unit7 情态动词.pptVIP

Verbs ;2) 连系动词 有词义，不能单独作谓语，必须和表语一起构成谓语。如：be, look, get, grow, turn, become, seem, keep, feel, sound, taste, smell, remain等。 His mother is a teacher of English. 有些动词既可作连系动词，又可以作及物动词或不及物动词。 He looked sad at the news. He looked sadly at the sick boy.;The silk feels soft. The tailor felt the silk. 3. 助动词 没有词义，不能单独作谓语，只能与别的动词一起作谓语来表示谓语的时态、语态、语气等， 或帮助构成否定式或疑问式。 How do you like this film? The hospital was built in 1995.;情态动词：Modal Verbs;一. can could 1. can　/ could 表示能力(过去时用could). be able to可以用于各种时态(可用现在、过去、将来) No one can do the work. He couldn’t swim when he was a boy, but now he has been able to swim well. can表示与生俱来的能力，不能用将来时 be able to 经过努力后能够,成功地做了某事时.　 高考题：Soon the fire spread , but everyone ____ get out of the burning house. A. could B. should C. was able to D. might ;2.表示允许= may=be allowed to // Can I come in? // You can go now. 3.表示客观可能性，表推测或惊异、怀疑、不相信态度，常用于否定，疑问句 //--- Can it be true? --- It can’t be true. // How can you be so careless? //Someone is knocking at the door. Who can it be? 4. can’t /couldn’t have done 对现在/过去事情的推测 // He can’t have said so. // The road isn’t wet. It couldn’t have rained last night. ; 5.比较委婉客气地提出问题或陈述看法，用could // Could you lend me your ruler? // I could come earlier, if necessary. ;二. May might 1.表允许，许可 //--- May I smoke here? 肯定回答： --- Yes, you may./ Yes, please. (Certainly, of course.) 否定回答： No, you mustn’t./ No, you may not. 2.表示一件事或许会发生，可能存在。“也许” // She may not be there today. // I may go there tonight, but I’m not sure. // You might have some fever. ;3.may as well= might as well 最好，不妨 might口气婉转，实现可能性更小 // You might as well speak your mind. // You may as well leave now. 4. may/might have done 对过去发生行为的猜测 也许已经做过某事（不是很确定） He may have gone home, for his bag isn’t here. 他也许已经回家了，因为他的包不在这里。;must /have to 1.两词都是‘必须’的意思，have to 表示客观的需要， must 表示 说话人主观上的看法，既主观上的必要。 My brother was very ill, so I ha