auxiliary-助动词

1、Auxiliary and Modal Verbs助动词auxiliary助动词包括以下几种：behavedoWill, shall, would, shouldCompany Logo1.助动词be的用法(1)与现在分词构成进行时态He is singing.They were having a meeting at ten yesterday morning.(2)与过去分词构成被动语态This kind of car is made in Beijing.Were the kids taken good care of?Company Logo(3)“be +不定式”表示未来的计划或安排

2、，还可表示命令或约定。The train is to leave at ten.You are to explain this.Company Logo2.助动词have 的基本用法(1)与过去分词构成完成时态I have finished my homework.The train had left before he got to the station.(2)与“been + 现在分词”构成完成进行时态It has been raining the whole morning.Company Logo(3)与“been +过去分词”构成完成时态的被动语态The story has bee

3、n told in China for many years.Company Logo3.助动词do 的基本用法(1)在一般现在时和一般过去时中构成疑问式及其回答。Do you usually go to school on foot? Yes, I do.What did he do yesterday ?(2)在一般现在时和一般过去时中构成否定。He doesnt like playing football.They didnt come here this morning.Company Logo(3)在肯定句的谓语动词前表示强调。Do come here tomorrow.Do be

4、quiet! 请安静！(4)在so, neither, nor开头的句子中构成倒装句。He didnt go to the party. Neither did I.She likes pop music. So do I .Company Logo4.助动词shall (should) 和will (would) 的基本用法(1)will 和shall 作为助动词可以和动词原形一起构成将来时态。I shall go home .Will they have anything to do this evening?Company Logo(2)should 和would分别是shall和wil

5、l 的过去式，通常用来构成过去将来时。I telephoned him yesterday to ask what I should do the next day.She said she would come .Company Logo几乎所有的助动词都可用于反意疑问句的附加问句中。You often write to her, dont you?He is reading a book, isnt he?They have been to Hainan, havent they?Lets go home，shall we?Company LogoExercise 确定下列句子中划线部分是

6、不是助动词：1. I had a boring afternoon yesterday.2. I had my watch stolen last night.3. He said he would return, and he did return.4. Its odd that you should mention that.5. Shall I open the window?6. She was criticised by the teacher.7. He will do anything for money.Company Logo情态动词Modal auxiliary情态动词有四

7、类：只做情态动词：must, can(could), may(might), 可做情态动词又可做实义动词：need, dare可做情态动词又可做助动词：shall(should), will(would)具有情态动词特征：have(had) to, used to, ought toCompany Logo情态动词无人称和数的变化, 情态动词后面跟的动词需用原形,否定式构成是在情态动词后面加 “not”。 He could be here soon. We cant carry the heavy box. 个别情态动词有现在式和过去式两种形式, 过去式用来表达更加客气, 委婉的语气, 时态性

8、不强, 可用于过去，现在或将来。 Company Logocan和could的用法 1. 表示能力或客观可能性，还可以表示请求和允许。如： Can you finish this work tonight? Man cannot live without air. Can I go now? Yes, you can. 注意：could也可表示请求，语气委婉，主要用于疑问句，不可用于肯定句，Could I come to see you tomorrow? Company Logo答语应用can 如：Yes, you can. （否定答语可用No, Im afraid not.）can表示能力

9、时，还可用be able to代替。如： Ill not be able to come this afternoon.Company Logo2. 表示惊异、怀疑、不相信的态度。（主要用在否定句、疑问句或惊叹句中） Can this be true? How can you be so careless! 3. “can(could) + have + 过去分词”的疑问或否定形式表示对过去发生的行为怀疑或不肯定。如： He cannot have been to that town. Company Logomay和might的用法 1. 表示许可。 表示请求、允许时，might比may的语

10、气更委婉一些，否定回答时要用Im afraid not表示委婉谢绝。如： You may drive the car. Might I use your pen? No, Im afraid not. 2. 用于祈使句中表示祝愿。如： May you succeed! Company Logo3. 表示推测、可能（疑问句不能用于此意）。 He may be very busy now. 4. “may(might) + have + 过去分词”表示对过去发生的行为的推测。如： He may not have finished the work. Company Logomust和have to

11、的用法 1. 表示必须、必要。（must表示主观多一些而have to则表示客观多一些）如： You must come in time. 回答must引出的问句时，如果是否定的回答，不能用mustnt，而要用neednt或dont have to。 Must we hand in our exercise books today? Yes, you must. (No, you dont have to.) Company Logo2. “must be + 表语”的结构表示推测，它的否定或疑问式用can代替must。 This must be your pen. 3. “must + ha

12、ve + 过去分词”的结构常用在肯定句中，表示对过去发生的行为的推测。它的否定或疑问式用can代替must。 He must have been to Shanghai. Company Logo4. have to的含义与must相似，两者往往可以互换使用，但have to有各种形式，随have的变化而定。must与have to有下列几点不同： must表示的是说话人的主观看法，而have to则往往强调客观需要。如： The play is not interesting. I really must go now. I had to work when I was your age.

13、Company Logo must一般只表现在，have则有更多的时态形式。 二者的否定意义不大相同。如： You mustnt go. 你可不要去。 You dont have to go. 你不必去。 询问对方的意愿时应用must。如： Must I clean all the room? Company Logodare和need的用法 1. need表示“需要”或“必须”，作情态动词时，仅用于否定句或疑问句中，在肯定句中一般用must, have to, ought to,或should代替。 You neednt come so early. Need I finish the wo

14、rk today? Yes, you must. 注意：neednt + 完成式“表示本来不必做某事而实际上做了某事”。如： You neednt have waited for me. Company Logo2. Dare作情态动词时，主要用于疑问句、否定句和条件从句中，一般不用在肯定句中。如： How dare you say Im unfair. He darent speak English before such a crowd, dare he? 3. Dare和need常用作实义动词，有时态、人称和数的变化，作实义动词时，dare后面通常接带to的不定式如： I dare to

15、 swim across this river. He does not dare to answer. Company Logoshall和should的用法 1. Shall用于第一、第三人称疑问句中，表示说话人征求对方的意见或向对方请示。如： Shall we begin our lesson? When shall he be able to leave the hospital? Company Logo2. Shall用于第二、第三人称，表示说话人给对方命令、警告、允诺或威胁。如： You shall fail if you dont work harder. （警告） He sh

16、all have the book when I finish reading. （允诺） He shall be punished. （威胁） Company Logo3. Should表示劝告、建议、命令，其同义词是ought to；在疑问句中，通常用should代替ought to。如： You should go to class right away.Should I open the window? Company LogoShould的三种特殊用法 情态动词should用于第一人称时可以表示说话人的一种谦逊、客气、委婉的语气。 I should think it would be

17、 better to try it again. I should advise you not to do that. Company LogoShould还可以用在if引导的条件从句，表示一件事听起来可能性很小，但也不是完全没有可能。相当于“万一”的意思。从句谓语由should加动词原形构成，主句谓语却不一定用虚拟语气。如： Ask her to ring me up if you should see her. If you should change your mind, please let us know. Company LogoWhy(or How) + should结构表示说

18、话人对某事不能理解，感到意外、惊异等意思。意为“竟会”。如： Why should you be so late today? Where is Betty living? How should I know? Company Logo4. “should + have + 过去分词”结构一般表示义务，表示应该做到而实际上没有做到，并包含一种埋怨、责备的口气。如： She should have finished it. I should have helped her, but I never could. You should have started earlier. Company L

19、ogowill和would的用法 1. 表示请求、建议等，would比will委婉客气。如： Would you pass me the book? 2. 表示意志、愿望和决心。如： I will never do that again. They asked if we would do that again. Company Logo3. 用“will be”和“will(would) + have + 过去分词”的结构表示推测，主要用于第二、三人称。前者表示对目前情况的推测，后者表示对已经完成的动作或事态的推测。如： This will be the book you want.The

20、guests would have arrived by that time. Company Logo4. Would可表示过去反复发生的动作或某种倾向。Would表过去习惯时比used to正式，并没有“现已无此习惯”的含义。The wound would not heal. During the vacation he would visit me every week. Company Logoought to的用法 1. Ought to表示应该。如： You ought to take care of him. 2. 表示推测。注意与must表示推测时的区别： He must be at home by now. （断定他已到家） He ought to be home by now. （不十分肯定） Company Logo3. “ought to + have + 过去分词”表示过去应做某事而实际未做。如： You ought to have asked him (but you didnt). 这时，ought to和should可以互相换用。 注