高中英语情态动词用法归纳与练习A: can / could = be able to1 表示能力两种时态can (could)，其他时态要用be able to的形式He can speak French.Was/were able to 可以表示成功做成某事的含义* managed to do / succeede d in doingWith our help, he was able to build the house.2 表示请求或许可Could 比Can 更加客气* mayCan I go now Yes, you can.3 表示推测或可能性，常用于否定句和疑问句Can he be at school？Today is Sunday. He can't be at school.Can’t couldn’t/ Can Could have doneThere is no light in the room. Can she have gone to bed？She can’t have gone to school----- it’s Sunday.Could have done 可用在肯定句中表示过去存在的可能性* may have done She could have gone out with some friends yesterday.Could have done 可以表示虚拟语气某事可能发生（并没有发生）It was silly to throw the TV out of the window. It could have hit somebody. 批评某人没有完成某事(本可以做某事)You are late again. You could have got up earlier.4 can 表示客观上的可能性*Anybody can make mistakes.B: may and might1 表示请求和允许类似用法can could(更加口语化)May I watch TV now Yes, you may.2 表示可能性; 猜测might比may更加不确定may/might have done 对过去的揣测*He may be busy these days.May not 可能不；不可能；一定不可3 表示祝愿Wish you success!May you succeed!*C: must and have to1 表示必须；一定要可以用have to 代替must 现在；将来的必须而且是主观看法*have to 有多种时态而且强调客观情况I really must stop smoking now.I had to leave early because I wasn’t feeling well.Must I come here？Yes, you mus t. No, you needn’t. needn’t / don’t have to must not 一定不能做某事mustn’t2 must 表示推测意思非常肯定“一定是”“一定会”It must be raining outside.Must have done 对过去/完成的推测* must have done, didn’t / hasn’tMust be doing 推测现在正在进行He must have gone over the article, hasn’t he？It must have rained last night, didn’t itD: need and dare 过去时dared情态动词和实意动词的区别A 人称变化B do / to doC 直接否定/ 间接否定can workNeed /dare 肯定句中，实义动词She needs to do it. I dare to do it.使用在否定句,疑问句中，情态动词，实义动词。
I dare not do it. I don’t dare (to) do i t.I need not do it. I don’t need to do it.1 need 情态动词无时态；人称的变化多用于疑问句和否定句You needn’t try to explain.Needn’t = don’t have toNeedn’t have done sth 过去本不必做某事* 虚拟语气2 need 实义动词有时态；人称的变化后接to do You need to tell us the t ruth.The car needs repairing. The car needs to be repaired.3 dare 情态动词过去时dared 无人称的变化多用在疑问句和否定句Dare he tell them what he knows？4 dare 实义动词有时态；人称的变化后接to do用于疑问句和否定句时其后的to 有时可省略Do you dare (to) jump off the high wallE: will and would1 表示征求对方(第二人称)意见或询问对方意愿would 比will 更客气委婉Will you have some more wine？Would you mind my smoking here？2 will 表示习惯性动作或某种倾向would 表示过去习惯性动作或某种倾向Fish will die out of water.When I was young, I would play badminton on Sundays.Would 与used to 的区别*Would 只能用来表示重复的动作而不能表示状态Used to 既可表示动作也可表示状态, 强调现在不如此He used to be a university student.3 will 表示意愿决心I will never do that again.F: shall, should and ought to1 shall 在问句中表示征求对方意见或请求用于第一，三人称What shall we do now？2 shall 肯定句中表示说话人强烈的感情允许，命令，禁止和威胁*或表示按规定，规章和义务等用于第二，三人称If you dare to do that, you shall be punished.These rules shall be obeyed.Shall not 禁止，不许3 shall 决心，意愿= willI shall come if I want to.4 should 表示劝告，建议= ought to 应该You should wash your hands first.Should 主要表示主观看法*Ought to 客观情况法律、规定、义务的使用Should have done / ought to have done sth 虚拟语气*Shouldn’t have done / ought not to have done sthYou should have done it today.5 should 推测推论可能性= ought to *估计They should/ ought to be there by now.6 should说话人的感情。
如惊奇、愤怒、失望等、“竟然”否定句疑问句You can’t imagine that well-behaved gentleman should be so rude to a lady Why should he do such a thing推测肯定性可能性由强到弱must / shall* / ought to / should / would* / could* / may / might /can 理论上的可能/ can Could / can’t couldn’tmust 用于表示"必定"，"必会"：All mankind must die.(表示必然会发生的事)所有的人一定会死的。
shall用于表示"必定"：I shall be rich one day. (shall be )总有一天我发达的。
ought to / should用于表示"想必会"(语气较must 弱)：They should / ought to be there by now.他们想必已到那儿了。
will 和would 用于表示"预测"或"习惯性"：I think he will be all right now. (will be 表示一定会)我想他现在一定好了。
Could 表推测No, but the shop could be in the east of the city.may 和might 用于表示"事实上的可能性"或"预测"：It may snow later this afternoon. (表示预测)今天下午可能会下雪。
You might be right. (表示有可能)你可能是对的。
Can理论上的可能Anybody can make mistakes. (只表示理论上的可能性)任何人都可能犯错误。
Can Could / can’t couldn’t 疑问否定He can't be at home. (否定句)他不可能在家。
Can the news be true (将情态动词can 置于主语the news 前就成疑问句) 这消息可能是真的吗？情态动词be doing情态动词have donemust / could / may / might / Can; could have done / can’t ; couldn’t have done请求和允许Can could I; he /may might I; he / will would you / shall should ought to I; he / Must I？不同类型语气分析Can I go with you (请求)我能跟你一起走吗？Could I ask you something (请求,用could 比can 更婉转)我可以问你一件事吗？May I make a suggestion ？我可以提个建议吗？Might I take a look of your work ？我看看您的大作行吗？Will you kindly tell me the way to the post office (表示客气请求)请问到邮局怎么走？Would you give me your address (用would 比will 表示更客气)请你告诉我你的地址，好吗？Shall we talk？我们谈谈好吗？What should we do next (用should 比shall 表示更客气)下一步我们该怎么做？Shall he come to see you (用于第三人称疑问句)要不要他来看你？Must I finish the work right now？Must I pay now (用于疑问句) (如回答不必时，需用needn't 或don't have to)我现在就得付款吗…情态动词的用法：表示“应该”、“必须”命令和建议（Must, have to , Shall, ought to, Should, May*, Might*,）Must 用于表示“必须”、“务必”：You must keep the place clean. (务必)你务必保持地方干净。