高中英语情态动词详解1. 表示请求和允许: can，could ，may，might. 过去式使语气更委婉，答语应用原形。
--- Could I use your computer tomorrow morning?--- Yes，you can.( 否定回答可用：No，I’m afraid not.)1)can表示理论上的可能性，指某事或情况可能发生，但并不说明实际上真的发生.Children can be very tiring.2)对现在事情的推测：情态动词+do对过去事情的推测：情态动词+have done对已完成事情的推测：情态动词+have done3)反意问句：He may know the plan，doesn’t he?You must have studied English before，haven’t you?You can’ t have been caught in the rain last night，were you?3．can & be able to在肯定句中can表示有“能力”做，be able to表示通过想办法/努力等而能够做成了某一件事，相当于managed to do…或succeeded in doing sth.Birds can fly.The fire spread through the hotel very quickly but everyone was able to get out.4. may / might as well do sth“还是…好”、“不妨”You might as well tell me the truth. 你还是把真相告诉我的好。
5. must和have to1) must表示的是说话人的主观看法，而have to强调客观需要。
2）否定形式含义不同。
mustn’t禁止，不许可，don’t have to不必3) must 偏要（做令人不快的事）eg. Must you shout so loudly?6. shall和should1)表示说话人征求对方意见和向对方请示，用于第一、三人称。
When shall my father be able to leave hospital?Shall2) 用于第一、三人称2) 用于第二、三人称，表示说话人给对方的命令、警告、允诺或威胁以及说话人的决心。
You shall go with me (命令)/ You shall have the book when I finish it.33（允诺）He shall be punished （威胁）/ Nothing shall stop me from doing it. (决心)3) 规定（在条约、规则、法律）1)表示劝告和建议“应该”2) “按道理应当”“估计”(=ought to)They should be there by now，I think.3）用于第一人称表示说话人的一种谦逊、客气、委婉的语气。
I should advise you not do that.我倒是劝你别这样做。
4）在条件句中表示“万一”，主句不一定用虚拟语气。
Ask Tom to ring me up if you should see him. /Should I be free tomorrow，I’ll come.5）（Why / How + ）should 结构表示说话人对某事不能理解，感到意外、惊异等意思，意为“竟然”，也用在某些从句中。
It seems so unfair that this should happen to me.这种事竟然发生在我身上真不公平。
7. will 和would1)表示意志和意愿。
will 指现在，would指过去。
If you will listen to me，I’ll give you some advice.2)表示请求、建议，would比will委婉、客气。
Will (Would ) you please pass me the book?3)表示习惯性动作，“总是”“惯于”，will指现在，would指过去。
Fish will die without water.Every evening，she would sit by the window，deep in thought.4). 表示功能，意为“能” 或“行”The machine won’t work.5) 表示预料或猜想。
It would be about ten when he left home.猜想他离开家时大约十点。
8. would & used to1)表示过去持续的状态和情况用used to；would不与表示状态的动词连用。
There used to be a hospital here. / There would be a hospital here.( ×)2)would 常与often，sometimes，for hours等表示时间的副词（短语）连用。
We would sit in the yard every evening and listened to his story.3)used to 强调过去的行为同现在的对比，含有“过去怎样，而现在却不这样了”的含义. eg.He will not spend the money on books as he used to.9. dare 和need两者作为情态动词都不用于肯定句，常用于否定句、疑问句和条件从句中。
习惯用语I dare say（可能，或许，我揣测）除外。
实义动词用法同于一般动词。
但在否定句中，dare 后的to可省略，即：don’t / doesn’t dare(to ) do…. need 作为实义动词时，用在否定句中时，其后的to不能省略。
He dare go there alone. ( ×)He dares to go there.He dares not go there alone. ( ×)He dare not go there alone . / He doesn’t dare( to ) go there alone.He stood there without daring lift his head.(×)He stood there without daring to lift his head. 10．情态动词+ have done，表示过去比较：情态动词+ do ，表示现在或将来。
needn’t have done & didn’t need to do…She need not have come yesterday. 她昨天本不必要来的。
（但却来了）She didn’t need to come yesterday.她昨天不必来。
（实际上也没来）【各个击破】1. I lived with my sister this summer and didn’t have to pay rent. So I ____save my salary.A. couldB. wouldC. was able toD. should2. --- Look ，John’s fallen asleep.--- Oh，he ______ too late last night.A. might sit up b. should have sat up c. could sit up D. must have sat up3. On Sundays when I was a child ，Father and I ____ get up early and go fishing.A. couldB. wouldC. mightD. should观察内容的选择，我本着先静后动，由近及远的原则，有目的、有计划的先安排与幼儿生活接近的，能理解的观察内容。
随机观察也是不可少的，是相当有趣的，如蜻蜓、蚯蚓、毛毛虫等，孩子一边观察，一边提问，兴趣很浓。
我提供的观察对象，注意形象逼真，色彩鲜明，大小适中，引导幼儿多角度多层面地进行观察，保证每个幼儿看得到，看得清。
看得清才能说得正确。
在观察过程中指导。
我注意帮助幼儿学习正确的观察方法，即按顺序观察和抓住事物的不同特征重点观察，观察与说话相结合，在观察中积累词汇，理解词汇，如一次我抓住时机，引导幼儿观察雷雨，雷雨前天空急剧变化，乌云密布，我问幼儿乌云是什么样子的，有的孩子说：乌云像大海的波浪。
有的孩子说“乌云跑得飞快。
”我加以肯定说“这是乌云滚滚。
”当幼儿看到闪电时，我告诉他“这叫电光闪闪。
”接着幼儿听到雷声惊叫起来，我抓住时机说：“这就是雷声隆隆。
”一会儿下起了大雨，我问：“雨下得怎样?”幼儿说大极了，我就舀一盆水往下一倒，作比较观察，让幼儿掌握“倾盆大雨”这个词。
雨后，我又带幼儿观察晴朗的天空，朗诵自编的一首儿歌：“蓝天高，白云飘，鸟儿飞，树儿摇，太阳公公咪咪笑。
”这样抓住特征见景生情，幼儿不仅印象深刻，对雷雨前后气象变化的词语学得快，记得牢，而且会应用。
我还在观察的基础上，引导幼儿联想，让他们与以往学的词语、生活经验联系起来，在发展想象力中发展语言。
如啄木鸟的嘴是长长的，尖尖的，硬硬的，像医生用的手术刀―样，给大树开刀治病。
通过联想，幼儿能够生动形象地描述观察对象。
4. --- Many people in England love to give advice on weather reporting.--- Yes，but I think the weather office’s computers ___ be more accurate. (精确的)A. canB. mustC. ought toD. might5. --- Are you still going to Shanghai for the Spring Festival?--- Yes，but I really ____ because I have a lot of things to deal with.A. can’tB. mustn’tC. won’tD. shouldn’t6. –Well，I forgot to bring my dictionary here yesterday.-- Actually you ____ it here. You were not allowed to use it.A. needn’t bringB. needn’t have broughtC. didn’t need to bringD. don’t have to bring7. --- Shall I book the table for the dinner?---Yes，you____. The restaurant is always full of people.A. canB. willC. must d. need8. The poor boy ____ the test again；in that case，his mother will be very disappointed.A. must have failedB. might failC. could have failedD. should fail9. --- Why ____ it rain now? I ___ go to the concert at 7.--- What a pity!A. can；might notB. should；needn’tC. must；can’tD. need；mustn’t10. -- We need some fresh air，but the window open.-- _____I help you ?A. didn't；WillB. shan't；NeedC. mustn't ；MayD. won't；Shall11. -- What do you think of your nephew?-- He be very naughty but at the same time you __ help liking him.A. will；willB. won’t ；can’tC. may；mayD. can；can’t12. It was not possible that she____ go down，step by step down the unexpected stairs into the dark below.A. should dareB. should dare toC. must dareD. must dare to13. --- I am told that John had another car accident this morning.我国古代的读书人，从上学之日起，就日诵不辍，一般在几年内就能识记几千个汉字，熟记几百篇文章，写出的诗文也是字斟句酌，琅琅上口，成为满腹经纶的文人。