高中英语复习 情态动词学案

1、情态动词情态动词一、情态动词的语法特征1. 情态动词不能表示正在发生或已经发生的事情，只表示期待或估计某事的发生。2. 情态动词除ought和have夕卜，后面只能接不带to的不定式。3. 情态动词没有人称、数的变化，即情态动词第三人称单数不加-s。4. 情态动词没有非谓语形式，即没有不定式，分词等形式。基本用法can/could能力the cinema can seat 1,000 people.请求（一、二）-could i use your dictionary?许可(can)-yes, you can.一时的可能性our house is on the top of the hill,

2、 and in winter the winds can be pretty cold.惊讶how can you be so careless. be able to do 经过一番努力做成 the fire spread the building quickly but everybody was able to escape. can't .too.无论怎样也不为过 you can't be too careful when you cross the street.may/ might请求（一）may i join you?许可(may)if you wish to d

3、o it you may.祝愿may you be happy.may well 很可能 his appearance has changed so much that you may well not recognise him.may/ might as well 不妨 if that is the case, i may as well try.we may as well finish the job, now (that) we've got sofar with it.will/would请求（二）would you pass me the book?建议will you

4、have some tea?意愿、决心i will do anything for you./ he will give up smoking.倾向或习惯性动作oil will not mix with water./ he will surf the internet every night.would do过去常常，现状不详。used to do过去常常，现在不做。shal1（一、三）征询意见shall i turn on the light, mum?/ shall the boy wait?（二、三）允 诺i promise you shall see her again before

5、 long.命令she shall not stay under my roof!决心these people want to buy my house, but they shan't have it.规定each competitor shall wear a number.言告if you children won't do as i tell you, you shan't go to the party.shoulj应该children should obey their parents.d惊讶（有责备意味）i don't know why you s

6、hould think i did it.must必须you must see the doctor.偏要must you worry her with questions, just when she is busycooking dinner?必然会everyone must die.表推测(-)情态动词表推测的三种回能用于表推测的情态动词：must, can, could, will, would, may, might, should, ought to1 .在肯定句中一般用must (定)，may (可能)，might / could (也许，或许)。(1) he must/may/

7、might know the answer to this question?他一定/可能/也许知道这个问题的答案。(2) it is cold in the room. they must have turned off the heating.屋里很冷，他们肯定把暖气关了。2. 否定句中用 cant / couldn't(不可能),may not/might not(可能不)。(1) it can't/couldn't be the headmaster. he has gone to america.这不可能是校长，他去美国了。(2) he may not/mig

8、ht not know the scientist.他也许不认识那位科学家。3. 疑问句中用can/could (能?)。(1) could he have finished the task?他可能把任务完成了吗？(2) can he be at home now?他现在能在家吗？注：以上三种句式中情态动词的语气按程度都是依次递减的。might, could并非may, can 的过去式，而表示语气较为委婉或可能性较小。(-)情态动词表推测的三种瓯1 .对将来情况的推测，用|“情态动词+动词原形"|。(1) she must / may / might / could amve b

9、efore 5.5:00前她一定/可能/也许到。(2) she must/may/might/could walk miles and miles among the hills without meeting anyone.她一定/可能/也许会在山里一连走好几英里而遇不到一个人。2. 对现在或一般情况的推测，用|“情态动词+be”|, 情态动词+be doing，或情态动词 +动词原形”|。(1) he must / may / might / could be listening to the radio now.他一定/可能/也许正在听收音机。(2) he can't ( cou

10、ldn't) / may ( might) not be at home at this time.这个时候他不可能/可能不在家。(3) mr. bush is on time for everything .how can ( could ) he be late for the opening ceremony ?布什先生一向准时，这次开幕式他怎么可能迟到呢？3. 对过去情况的推测，用|“情态动词+ have +过去分词中(1) it must / may / might / could have rained last night .the ground is wet.地湿了，昨

11、晚肯定/可能/也许下雨了。(2) the door was locked. he can ( could ) not / may ( might) not have been at home .门锁着，他不可能/可能不在家。(3) can / could he have gotten the book?难道他找到书了吗？注：情态动词should /ought to表推测时，意为“想必会，理应”但与“have+过去分词”连用时，则又可构成虚拟语气意为“本应该做某事却没做”。例如：(4) it's seven o'clock. jack should/ought to be her

12、e at any moment.现在七点钟了，杰克理应随时到达。(推测)(5) she should / ought to have attended your birthday party, but she had to look after her mother in hospital.(虚拟)她本该出席你的生日晚会的，可是她得在医院照顾她妈妈。(6) tom should not /ought not to have told me your secret, but he meant no harm.(虚拟) 汤姆本不该告诉我你的秘密，可是他并无恶意。推测的句型特点(对某一次的推测句型有

13、两部分：语气和时态)(1)语气部分：(以下情态动词语气由强至弱)肯定句：must、may> might (=could)否定句：can't (=couldn,t)、mayn't、mightn't疑问句：can、could (语气更加委婉不确定)(2)时态部分：be表示对瓯的推测have done表示对|迂丢|的推测be doing表示对正在进行的推测表推测的情态动词用法“情态动词+完成时”是历年高考的热点，在做此类练习时，既需要掌握这一结构的基本 用法，乂应该仔细体会题干所提供的语言信息，准确理解语言环境和说话人的含义，尤其要 注意题干中时态给予的暗示。1. mu

14、st have done表示对已经发生的事情的推测，意为“一定，想必”，句子中表示的是一种 肯定的推测。这种结构一般只用于肯定句，其否定形式是can't (couldn't) have done ,表 示“不可能，肯定不会”。例如：he didn't hear the phone . he must have been asleep.他没有听到电话响，他肯定是已经睡着了。he must have been to shanghai.他一定去过上海。they can't have gone out, because the light is on .他们不可能出去，

15、因为灯亮着。2. can (could) have done表示对过去的时间内可能发生的事情的猜测，can have done 一般 只用于否定句和疑问句。could have done还可以用于肯定句，常用来表示本来可能完成而 实际未完成的动作。例如：he can't have finished the work so soon.这项工作他不可能完成得这样快。we could have walked to the station , it was so near .我们本来是可以走到车站去的，路很近。3. may (might) have done(1) 表示对已经发生的事情的不太肯

16、定的推测，意为“可能已经，或许已经”。(2) 虚拟用法表示本可以做，但却没做(表示很委屈地责备)if we had taken the other road , we might have arrived earlier.如果我们选择另一条路，我们可能会到得早一些。he might have given you more help, he was very busy.他本来是可以给你更多帮助的，尽管他很忙。4. neednt have done指实际上做了本来不必要做的事，意为“本来不必”。例如：there was plenty of time , she needn't have h

17、urried.时间很充裕，她本不必匆忙。you needn't have told him the news.他本来不必把这个消息告诉他。5. should （ought to ） have done指本该做而实际未做的事，意为“本来应该”。其否定式 shouldt （oughtn't） have done则表示某种行为不该发生但却发生了。例如：you should have started earlier , but you didn't.你本应该早一点出发，但是你没有。you ought to have helped him （but you didn't

18、）.你本应该帮助他。we shouldn't have waited for her because she never came.我们本不应该等她，因为她根本不会来。6. wouid have done本想做（却没做）wouldn9t have done本不想做（却做了）i would have helped you, but i was too busy.我本想帮你，但我太忙了。在虚拟语气中的用法1. should have done表示"过去本应该做某事却未做。”其否定结构shouldn't have done表示 “过去本不该做某事却做了。”2. ought to have done表示"过去本应该做某事却未做。”其否定结构oughtn't to have done表 示“过去本不该做某事却做了。”3. need have done表示“过去本有必要做某事却未做。”其否定结构needn*t have done表示 “过去本没必要做某事却做了。”