高中英语情态动词的用法（30张PPT）

Grammar---情态动词 概念： 表说话的语气，态度和看法，意愿等的词。 特点： 1. 没有人称和数的变化 2. 不能独立使用，它和后面的动词构成谓语，接动词原形 3. 变疑问句和否定句时，不需助动词，将情态动词直接移动至主语前变为疑问句，直接在情态动词后加not变否定 只作情态动词的 can/could, may/might, ought to, must 可情态可实义的　 need, dare/dared 可情态可助动词的　shall/should, will/would ·情态动词的语法特征 情态动词用法 (一) 1. can/could (1) 表能力；could为过去 I can easily tell my father's step. Mozart could play the piano at the age of 3. (2) 表许可，不拘礼节时用can,委婉时用could. ---Can /Could I use your phone?（请求许可） ---Yes, of course you can. You can have a short holiday after this item of work. (给予许可） These days children can do whatever they want. （陈述许可） （3）can 与could表示“有时会” It can get quite cold here at night James could be very annoying sometimes (3) can的习惯用法 can but /only 只好，最多不过 We can but do our best. cannot help but +do原 cannot help doing 不得不，不禁 I cannot help but often think of my parents. I couldn't help laughing at this. cannot....too 无论....都不过分；越....越好 not 可换成never We cannot thank you too much for what you have