高中英语语法情态动词复习（共29张PPT）

情态动词 一、情态动词的基本用法： 1. can/could 表示能力; Eg. He can speak three languages. She could swim at the age of 5. 表示客观的可能性； Eg. Accidents can happen to any drunken driver. Swimming in the lake can be dangerous. 表示请求和允许； Eg. Can I have a loolk at your new watch? Yes, of course you can. 表示请求时，口语中常用could代替can使语气婉转，但回答时仍用can； Eg. Could you please help me learn Englsih? Yes, I can. 表示惊讶、怀疑、不相信的态度（主要用于否定句、疑问句）； Eg. How can you believe such a liar as him? That can’t be true. 2. may/might 表示允许、许可；（否定回答用mustn’t, 表示“禁止”） Eg. May I listen to music while doing my homework? No, you mustn’t. 表示请求许可时，might比may的语气更委婉些； Eg. May/Might I trouble you to pass me the book? 表示可能性的推测，might比may的语气显 得更加不肯定； Eg. Tom may go to the cinema with us this evening. Tom might go to the cinema with us this evening. may 用于祈使句表示祝愿；