[高一英语]English Modal Verbs.ppt

English Modal Verbs （英语情态动词） (根据语用功能分类) The functions of the modal verbs （情态动词的功能） 能力(ability): can, be able to 许可(permission): may, can; might, could,(must not) 请求(request) : can, will, could, would 提议/提供(offering): would, can, may, shall 义务(obligation): should, ought to, must, need 可能(possibility): may, might, can, could, must, ought to, should; will 意愿(intention)：will, would 其它(others): dare（敢）, need（需要）, shall(许诺) 与过去事实相反: would, could, should, might, need I．Ability (能力)： can, be able to 1. Can 表示现有的，一般的能力，包括体能、智能、技能。通常可以用be able to 替换。例如： Can you stand on your hands? Are you able to stand on your hands? 但表示正在发生的动作只能用can, 而不用be able to。如： Look! I can stand on my hands. 2. Can不能用于表示将来才具备的一般能力 例如，我们不说： *I can speak English well in two years. (×) 应改为：I will be able to speak English well in two years. *You can swim soon if you practise every day. (×) 应改为：You will be able to swim soon if you practise every day. 但是，can可以表示现在断定将来能办到的具体事情。例如： Now I am busy. I can repair your car this afternoon. be able to 可用于不同的时态。例如： He is / was / will be able to talk to foreigners in English. 3. Could 表示过去的一般能力；was able to 表示过去的能力， 同时又表示这一能力得以实现。 He could / was able to walk when he was 8 months old. He could swim across the river easily, but he didnt. He was able to swim across the river.(= He succeeded in swimming across the river.) II．Permission (允许) 1.may, can, might, could表示“许可”, 均可用于疑问句, 以请求得到许可（ask for permission）。例如： Can / Could / May / Might I use your telephone? could和might的语气比较委婉，显得彬彬有礼。 2. 在非疑问句中，不用might和could 因为语气不肯定会让人感到态度“暧昧”。（哪怕是在答句中） If you need a bike, you may use mine. -- Could I stay out late tonight? -- No, you can’t. / Of course you can.(不能用could / couldn’t) 3．表示过去的“许可”。 极少用might He might not go there.实际上经常表示“他可能不 去那儿。” could可以表示过去的许可，但一般有过去时间状语。例如： This castle could be visited those days. 或用其他手段： We were not allowed to smoke when at school. 4.can not, may no