高中英语情态动词的用法（30张PPT）

课件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 done for us. You can never do the work too well.3. must/have to （1）必须，must 侧重主观，have to侧重客观 We must rely on ourselves. I can't see things clearly, so I have to wear glasses. (2)must 的否定为must not/mustn't, 意为禁止，不许 have to 的否定为don't have to, 意为不必 You mustn't take the books out of the reading room. You don't have to go now. 回答含有must 的问句时，肯定用must, 否定用needn't /don't have to Must I finish my work today? Yes, you must No, you needn't/ don't have to4. shall (1) 一，三人称做主语的疑问句中，表征求意见或请求 Shall I change into the evening dress for your party? Shall Tom go there with me tomorrow? (2) 二，三人称称述句中，表许诺，命令，警告，威胁等 You shall get an answer from me tomorrow. You shall be punished for what you have done.5. should （1）作为shall 的过去，用于一，三人称的问句中，多用于间接引语，征求意见。 Mr Lee asked if should get his visa on time. (2) 表义务，职责 The children should be taken good care of. (3) 提供帮助、建议 Should I help you with the community affairs？ （4）表惊奇，愤怒，失望等情感 It is surprising that Mary should love such a person as Jack.6. ought to 否定: ought not to/ oughtn't to 疑问：将ought置于主语前 You ought not to be late for such an important meeting. ought I to hand in my composition now?7. will和would： I will tell you something important. 我将要告诉你一些重要的事Will you tell her that I'm here? 请您告诉她说我在这儿，好吗? I told him not to do it, but he would.? （助动词）?（情态动词）will是助动词或是情态动词 用于构成将来时是助动词。 用于表“意志/决心/请求”是情态动词。 would亦同理，只是表过去。7. will / would (1) 表意愿，would为过去 --Can someone help me? --I will. They would not let him in because he was poorly dressed. (2) 与you连用，表请求、要求，won't you 加强语气；would 比will更委婉 Will/Would ... ...