助动词（Auxiliary Verb）：协助主要动词构成谓语动词词组的词。
自身没有词义，不可单独使用。
主要动词（Main Verb）：是被协助的动词，构成时态和语态。
He doesn't like English. 他不喜欢英语。
（doesn't是助动词，无词义；like是主要动词，有词义)最常用的助动词有：be, have, do, shall, will, should, would 等。
基本助动词只有三个：be, do, have他们没有词汇意义，只有语法作用，如协助构成进行时，完成时，被动态，否定句，疑问句等。
一、be 动词的用法既可作系动词，又可作助动词，做助动词有人称和数的变化，第一人称用am,第二人称及复数用are,第三人称及单数用is，am,is 过去式为was, are的过去式为were,它与现在分词构成进行时态和过去分词一起构成被动语态。
a. 表示时态be+doing（现在分词）表示现在进行的动作He is singing. 他正在唱歌。
b. 表示语态be+done(过去分词）表被动语态He was sent to England. 他被派往英国。
c. be+to do（动词不定式）表示计划安排命令。
We are to plant trees next week. 下周我们将要去植树。
You are to explain this 。
对此你要做出解释。
二、do的用法Do主要帮助实意动词构成否定和疑问句，后跟动词原形，有时放在实意动词前起强调作用，还可代替前文出现的动词，避免重复。
Do 有人称和数的变化，第一、二人称及复数用do，第三人称及单数用does，过去式为did。
1）构成一般疑问句。
DO +主语+动词原形+其他I like singing 变为疑问句为Do you like singing ?2）do + not 构成否定句。
主语+do +not +动词原形。
I do not want to be criticized.我不想挨批评。
He doesn't like to study.他不想学习。
Many students didn’t know the importance of English before. 过去好多学生不知道英语的重要性.3) 构成否定祈使句。
Don't go there.不要去那里。
Don't be so absent-minded.不要这么心不在焉。
说明：构成否定祈使句只用do，不用did和does。
4）放在动词原形前，加强该动词的语气。
Do come to my birthday party please.请一定来参加我的生日宴会。
I did go there.我确实去那儿了。
I do miss you.我确实想你。
我真想你了！5）用作代替动词。
---- Do you like Beijing? --你喜欢北京吗？---- Yes, I do.No,I don’t. --是的，喜欢。
（do用作代动词，代替like Beijing.）He knows how to drive a car, doesn't he? 他知道如何开车，对吧？三、have 的用法Have+过去分词构成完成时态I have studied english for a long time .情态动词的基本用法归纳情态动词有can (could), may (might), must, have to, shall (should, will (would), dare (dared), need (needed), ought to等。
情态动词无人称和数的变化；不能单独使用，必须与其后的动词原形构成谓语。
一、can, could1) 表示能力Mary can speak three languages.Can you skate?此时可用be able to代替。
Can只有一般现在时和一般过去式；而be able to则有更多的时态。
I’ll not be able to come this afternoon.当表示“经过努力才得以做成功某事”时应用be able to，不能用Can。
如：He was able to go to the party yesterday evening in spite of the heavy rain.2) 表示请求和允许。
-----Can I go now?----- Yes, you can. / No, you can’t.此时可与may互换。
在疑问句中还可用could,might代替，不是过去式，只是语气更委婉，不能用于肯定句和答语中。
---- Could I come to see you tomorrow?---- Yes, you can. ( No, I’m afraid not. )3) 表示推测（惊讶、怀疑、不相信的态度），用于疑问句、否定句和感叹句中。
Can this be true?This can’t be done by him.How can this be true?二、may, might1) 表示请求和允许。
might比may语气更委婉，而不是过去式。
否定回答时可用can’t或mustn’t，表示“不可以，禁止”。
----Might/ May I smoke in this room?---- No, you mustn’t.---- May/Might I take this book out of the room?---- Yes, you can. (No, you can’t / mustn’t. )用May I...？征徇对方许可时比较正式和客气，而用Can I...？在口语中更常见。
2）用于祈使句，表示祝愿。
May you succeed!3) 表示推测、可能性（不用于疑问句）。
might不是过去式，它所表示的可能性比may小。
1．He may /might be very busy now.2．Your mother may /might not know the truth.三、must, have to1) 表示必须、必要。
You must come in time.在回答引出的问句时，如果是否定的，不能用mustn’t（禁止，不准），而用needn’t, don’t have to（不必）.---- Must we hand in our exercise books today?---- Yes, you must.---- No, you don’t have to / you needn’t.2) must是说话人的主观看法，而have to则强调客观需要。
Must 只有一般现在时，have to 有更多的时态形式。
1．he play isn’t interesting, I really must go now.2．I had to work when I was your age.3) 表示推测、可能性（只用于肯定的陈述句）1．You’re Tom’s good friend, so you must know what he likes best.2．Your mother must be waiting for you now.四、shall, should1)shall +动词原形表示将来时态Shall we go shopping tomorrow?2) shall 用于第一人称，征求对方的意见。
What shall we do this evening?shall 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。
1. You shall fail if you don’t work hard.(警告)2. He shall have the book when I finish it.(允诺)3. He shall be punished.(威胁)六、will, would1) 表示请求、建议等，would更委婉。
Would you like a cup of coffee? 你想要一杯咖啡吗？2)will +动词原形表将来时态He will come back next month . 他下个月将会回来。
3）表示意志、愿望和决心。
1. I will never do that again.助动词练习题1 把下列句子变为一般疑问句。
1.It is a lovely dog.________________________________________ 2.She is lovely girl.________________________________________ 3.We are classmates.______________________________________4.I am a doctor.________________________________________ 5.There is a bird in the tree.________________________________6.They are good friends.____________________________________7.I love my parents._______________________________________ 9. We have a pleasant home._______________________________10.They go to church on Sunday._____________________________11.You are a singer.______________________________2. 用do does be 填空1> _____ she know all the answers ?Yes , she ____ . No, she _____.2> _____ the twins often fight ?Yes ,_____ do. No, _____ don’t.3> _____ your dad like listening to music?Yes ,____ does . No, _____ doesn’t.5> _____ you have a new teacher?Yes , I ______. No, I ______.6> _____ she a teacher?Yes, she _____ . No, she _____.10> _____ your father smoking in the living room?Yes, ____ is .No, he _____.助动词和情态动词专项练习一、情态动词的基本用法⒈Can John Smith ______ his homework on time?A. finishB. finishesC. finishingD. finished⒉She dare ______ out by herself at night.A. go notB. not to goC. to not goD. not go⒊You ______ to the party tonight if you have something important to do.A. don’t need comeB. needn’t to comeC. needn’t comeD. don’t need coming⒋—We’ll be ready to leave at eight.—Well, John must ______ back by then.A. beingB. isC. beD. to be⒌Your grandmother ______ the newspaper without glasses.A. can still readB. cans still readC. still can readsD. can still reads二、must, need, dare的用法⒍—Must I get up early tomorrow, Dad?—No, you _____. Tomorrow is Sunday.A. can’tB. mustn’tC. needn’tD. couldn’t⒎—Must we finish the book today?—Yes, you ______.A. canB. mayC. needD. must⒏You ______ play on the road. It’s dangerous.A. mustn’tB. mayC. canD. must⒐You ______ return the book now. You can keep it until next week.A. can’tB. mustn’tC. needn’tD. dare not⒑I ______ a sleeping bag because I’ve already got one.A. needn’t haveB. didn’t haveC. don’t needD. need not⒒Mr Smith ______ a pen from Jack.A. must to borrowB. had borrowedC. must borrowedD. had to borrow三、can, could, may, might的用法⒓The man ____ walk fast because he is lame in the right foot.A. mustB. mustn’tC. canD. can’t⒔—Could I borrow your dictionary?—Yes, of course you ______.A. willB. wouldC. mustD. can⒕A computer _____ think for itself, it must be told what to do. A. might not B. may not C. couldn’t D. can’t⒖—That must be a mistake.—I don’t think so. It ______ a mistake.A. may be notB. needn’t beC. cannot be⒗He ______ help crying at the news of his father’s death.A. couldn’tB. shouldn’tC. hadn’tD. didn’t⒘“Now, ______ all smile, please?” he asked.A. may youB. do youC. shall youD. can you⒙I haven’t brought my dictionary with me. _____ I use yours?A. MustB. ShallC. MayD. Need四、should, would, shall, will的用法⒚—Must I copy the new words in class?—No, you ______. You ______ do it at home.A. needn’t, mayB. mustn’t, mustC. mustn’t, mayD. needn’t, mustn’t⒛—Would you please not draw pictures on the wall?—Sorry. I ______ it again.A. am not doingB. don’t doC. didn’t doD. won’t do21.______ I open the window? It’s so warm here.A. ShallB. WillC. WouldD. Must22.______ you like some oranges?A. WouldB. CanC. MayD. Must23.Tom said that he ______ apologize to Mary.A. wouldB. willC. shallD. is going to24.“Do you think we ______ turn back?” Jane asked.A. shallB. willC. shouldD. would⒈He ______ any help. He can do it all by himself.A. needs notB. needn’tC. doesn’t needD. doesn’t need to ask⒉Li Fang isn’t in the classroom. He ______ be at the library. Let’s go and find him.A. canB. mustC. needD. should⒊—May I have a look at your new watch ?—Yes, you ______.A. canB. mustC. needD. should⒋—Must I hand in the exercise book tomorrow ?—No, you______. You can hand it in the day after tomorrow.A. can’ tB. mustn’tC. needn’tD. couldn’t⒌There ______ an English test next Monday.A. maybeB. wasC. may beD. may⒍You’d better ask someone, or you______ get lost.A. mayB. mustn’tC. are going toD. can7.“Come on!” Peter called. “We ______ stay here any longer.”A. couldn’tB. can’tC. hadn’t toD. mightn’t8..Must Tom write it now? No, he ______.A. needn’tB. can’tC. mustD. mustn’t9.“Have you seen Li recently?”“No, I think he must ______ away on vacation.”A. beingB. isC. beD. to be10.“All right. You ______ if you don’t want to.”A. don’t need stayB. needn’t stayC. needn’t to stayD. don’t need staying 1：She ________ to see documentaries（记录片）.A、do wantB、don't wantC、doesn't wantD、not want2：Look at that picture on the wall. __________ you like it?A、DoB、CanC、CouldD、Are3：He ________ like pears.A、doB、isC、doesn'tD、not4：—Do you often go to the cinema______ Sunday?—No, we__________.A、on, don'tB、on, aren'tC、in, doD、in, don't5：－Can you see a light on the table?－Yes, ________.A、I amB、I’m notC、I canD、He isn’t6：—Does the boy want to be an actor? —________.A、Yes, he isB、No, he doesC、Yes, he doesD、No, he isn't7：_________ he have any apples ?A、DoB、DoesC、IsD、Are8：She ______ want to be a policewoman, because she thinks it’s kind of dangerous.A、isn’tB、aren’tC、don’tD、doesn’t9：Why＿＿＿＿he have brown hair?A、doB、doesC、isD、has10：What time__________ he get home every day?A、isB、doesC、doD、am11：What________ you see in the picture?A、isB、areC、canD、have12：Jack_______ like flying kites______ throwing a frisby.A、don't, orB、doesn't, andC、don't, andD、doesn't, or13：A：________ Jim ________ a ball?B：No, he________.A、Do, have, don'tB、Does, has, doesn'tC、Is, have, isn'tD、Does, have, doesn't14：I ________ have a watch.A、am notB、doesC、don'tD、doesn't15：＿＿＿＿you＿＿＿＿a good time on your vacation?A、Did; haveB、Did; hadC、Were; haveD、Were; had16：Simon likes _____ football, but he doesn’t _____ it well.A、play, playsB、to play, playsC、plays, playingD、playing, play 17：She＿＿＿＿have to wash the dishes now.A、don'tB、notC、doesn'tD、can't18：—________Colin ________ Chinese history? —Yes, he does.A、Do; likeB、Does; likesC、Do; likesD、Does; like19：Li Lei ______ lunch at home.A、hasn’tB、haven’tC、don’t haveD、doesn’t have20：－Who cleaned the blackboard yesterday, Dick? －John＿＿＿.A、cleanedB、doesC、didD、is21：__________ you usually come to school by bike?A、Don'tB、Doesn'tC、Aren'tD、Isn't22：－Where______lions come from? －I think they come from Africa.A、areB、isC、doesD、do23：__________ we have any eggs?A、Aren'tB、Don'tC、Can'tD、Mustn't24：＿＿＿＿you on your vacation yesterday?A、AreB、WereC、WasD、Did25：－Who＿＿＿＿dinner last night? －My mother＿＿＿＿.A、cooked; didB、did; cookedC、did; didD、cooked; cooked1.There __________ a meeting tomorrow afternoon.A. will be going toB. will going to beC. is going to beD. will go to be2.Mother ________ me a nice present on my next birthday.A. will givesB. will giveC. givesD. Give3.Listen! The girl _____________ in the room.A. singsB. singingC. is singingD. are singing4.What are you doing? I’m __________ TV.A. watchB. watchesC. to watchD. Watching5.In our school there are fifty-five ___.A women teachers B. woman teachers. C women teacher D. woman’s teacher6.Jack went to have two ___ pulled out yesterday afternoon.A. toothsB. toothC. teethD. Toothes7.Many ____ have been built in our city since 1987.A. factorysB. factoriesC. factoryesD. factorys8.Who's that at the door? ____ is the postman.A. SheB. ThisC. ItD. He9. you go to the movies yesterday?A.DoB.DidC..DoesD.Have。