八、动词(第四节 情态动词的概念和用法).ppt

导练互动,第四节 情态动词的概念和用法,.情态动词的基本概念情态动词表示说话人对某一动作或状态的态度，具有一定的感情色彩。 情态动词具有以下特点：(1)有一定词义；(2)不受主语人称和数的变化影响；(3)后跟动词原形一起构成谓语(ought to除外)，不能单独充当谓语。,.情态动词的基本用法 1can (could)(1)表示能力，could主要指过去时间。如：Two eyes can see more than one. 两只眼比一只眼看得清。 Could the girl read before she went to school? 这女孩上学前能识字吗？,(2)表示可能(理论上或逻辑判断上)。如：He cant (couldnt) have enough money for a new car. 他不可能有足够的钱买辆新车。 You mustnt smoke while youre walking around in the wood. You could start a fire. 在林子里走时勿吸烟，那样可能会引起火灾。,(3)表示允许。如：Can I have a look at your new pen? 我可以看一看你的新钢笔吗？ He asked me whether he could take the book out of the reading room. 他问我是否他可以把书带出阅览室。 (4)表惊异、怀疑、不相信等态度。主要用于否定句、疑问句或感叹句中。如：He cant (couldnt) be over sixty. 他不可能超过六十岁。 How can you be so careless? 你怎么这么粗心？,(5)比较委婉客气地提出问题或陈述看法。如：Can (Could) you lend me a hand? 帮我一把好吗？ Im afraid we couldnt give you an answer today. 恐怕我们今天不能给你答复。,2may (might) (1)表允许，might可以指过去时间，也可指现在时间，语气更委婉。如：You may take whatever you like. 你喜欢什么就拿什么。 He told me that I might smoke in the room. 他告诉我可以在房间里抽烟。 在回答以may引起的问句时，多避免用这个词，而用其它方式，如Yes, please. / Certainly. / Please dont./ Youd better not. / No, you mustnt.等，以免显得太严肃或不客气。,(2)表可能(事实上)。可以指过去时间，也可以指现在时间，但语气更加不肯定。如：He may be at home. 他可能在家。 She may not know about it. 她可能不知道这件事。,即学即用1：(1)May I try on the jeans? Yes, you _. A. shouldB. can C. must D. need(2)May I go surfing alone this afternoon, Dad? No, you _.Its dangerous. A. may notB. cant C. neednt D. dont,B,B,(3)He _ speak a little French when he was five. A. can B. could C. may D. must (4)Our teacher _ be in the office, I saw her leave just now. A. can B. must C. cant D. mustnt,B,C,(5)_ you please not speak loudly in the library? Sorry, I wont. A. CanB. Could C. MayD. Must(6)Dad,_I play badminton with Bobby now? Yes, you can. But you have to come back before supper. A. mustB. may C. needD. should,B,B,(7)_ I take the magazine out? Im sorry. you _ read it here. A. Could .couldB. Might.might not C. Could.can D. May.must(8)Peter _ come with us tonight, but he isnt very sure yet. A. must B. can C. may D. will,D,C,3must (1)表示义务。意为“必须”(主观意志)。如：We must do everything step by step. 我们一切都必须循序渐进地做。 You mustnt talk to her like that. 你不可能那样对她说话。回答以must引起的问句，通常不用mustnt, mustnt 表示禁止、不许可的含义。如：Must we hand in our exercise books now? 我们现在就要交练习本吗？ No, you neednt. / No, you dont have to. 不必。,(2)表示揣测。意为“想必、准是、一定”等，只用于肯定句。如：He must be ill. He looks so pale. 他准是病了。他的脸色苍白。 Shes wearing a diamond necklace. She must have a lot of money. 她戴着钻石项链，一定很有钱。,4need作为情态动词常用于否定式中，neednt意为“不需要”。,即学即用2：(1)Come on! We _ hurry because there isnt much time left. A. may B. must C. can D. need(2)When traffic lights are red, we _ stop and wait. A. may B. can C. must D. might,B,C,(3)Must I clean the classroom right now? No, you_. A. dont B. cant C. needntD. mustnt(4)May I park my car here, Sir? _.You may park it over there. A. Yes, you may B. Yes, you can C. No, you needntD. No, you mustnt,C,D,(5)All the lights are on, the Smiths _ up. A. must get B. is getting C. must be getting D. would get(6)Lets go to the Museum by taxi. We _ take a taxi. Its not far from here. A. cantB. neednt C. couldntD. mustnt,A,B,5shall (1)表征询意见，用于第一人称疑问句。如：Shall I get you some tea? 我给你点茶好吗？ What shall we do this evening? 我们今晚做什么？,(2)表说话人的意愿，有“命令、允诺、警告、决心”等意思，用于第二人称陈述句。如：You shall do as I say. 按我说的做。(命令) You shall have my answer tomorrow. 你明天可以得到我的答复。(允诺) Nothing shall stop us from carrying out the plan. 什么也不能阻止我们执行这项计划。(决心),即学即用3：When and where _ we meet?Lets meet at 800am. outside the school gate, _ we?,shall,shall,6will(1)表意愿，用于各种人称陈述句。如：I will do anything for you. 我愿为你做任何事。 If you read the book, Ill lend it to you. 如果你愿意读这本书，我会把它借给你。用neednt或dont have to.(2)表请求，用于疑问句。如：Will you close the window? Its a bit cold. 请你把窗户关上好吗？有点冷。 Wont you drink some more coffee? 再来一点咖啡好吗？,(3)表示某种倾向或习惯性动作。如：Fish will die out of water. 鱼离开水就不能活。 The boy will sit there hour after hour looking at the traffic go by. 那男孩常常坐在那里好几个钟点，看着车辆行人通过。,即学即用4：(1)The Greens _ to China for vacation next month. A. came B. coming C. will comeD. come(2)I _ until the one I love come. A. wont wait B. will wait C. wait D. is waiting,C,B,(3)Dont give up. Studying hard _ you succeed. A. must makeB. is making C. will make D. made(4)There _ a talent show in our school next Friday. A. is going to haveB. was C. will be D. will have,C,C,7should (1)表义务。意为“应该”(某件事宜于做)，用于各种人称。如：You should be polite to your teachers. 你对老师应该有礼貌。 You shouldnt waste any time. 你不应该浪费时间。 (2)表推测，意为“想必一定、照说应该、估计”等。如：The film should be very good as it is starring first class actors. 这部新电影是一流演员主演的，估计拍得很好。 They should be home by now. 照说他们现在应当已经到家了。,即学即用5：(1)Tomorrow is my mothers birthday. What _ I get for her? A. may B. shall C. should D. might(2)We _ throw litter about in public. A. may not B. couldnt C. wouldntD. shouldnt,C,D,8would (1)表意愿。如：They would not let him in because he was poorly dressed. 他们不让他进去因为他衣着破旧。 I said I would do anything for you. 我说过我愿意为你做任何事。 (2)表委婉地提出请求、建议或看法。如：Would you like another glass of beer? 再来杯啤酒好吗？ Would you mind cleaning the window? 请把窗户擦一下好吗？,(3)表过去反复发生的动作或过去的一种倾向。如：Every time she was in trouble, she would go to him for help.她每遇到麻烦都会向她求助。即学即用6：_ you like to go out with me.Yes, Id love to.A. WillB. CanC. HadD. Would,D,9ought to (1)表义务，意为“应该”(因责任、义务等该做)，口气比should稍重。如：You are his father. You ought to take care of him. 你是他父亲，应当管他。 You oughtnt to smoke so much. 你不应该抽这么多烟。,(2)表推测，暗含很大的可能，语气较弱。如：Han Mei ought to know his telephone number. 韩梅该知道他的电话号码。 Theres a fine sunset, it ought to be a fine day tomorrow. 今天有晚霞，明天应该是个好天。 即学即用7：As a student you _ _ do your homework on time.,ought to,.几组词的辨异1can 和be able to(1)情态动词can只有两种时态形式，现在式can和过去式could，而be able to有多种时态形式。如：Mary can play the piano. She has been able to play it since she was 5.玛丽会弹钢琴。她五岁起就会弹了。,(2)用在过去时中，could经常表示能够做某事，事实上不一定去做，而waswere able to则表示“过去做成了某事”。在否定句中两者可通用。如：He could swim across the English Channel. But he didnt feel like it that day. 他能游过英吉利海峡，但那天他不想游。 Yesterday I was able to get home before the heavy rain. 昨天我在下大雨前赶到了家里。,即学即用8：(1)The fire spread through the hotel very quickly but everyone _ get out. A. had to B. would C. could D. was able to(2)Ill _ arrive there before the meeting begins. A. can B. able to C. be ableD. be able to,D,D,2must和 have to must表示主观意志，而have to表示由于客观因素不得不做某事，强调客观原因或外力的影响。must没有过去式。 I told her that she must give up smoking. 我叫她必须戒烟。 We had to get everything ready that night. 我们那晚得把一切准备就绪。,即学即用9：(1)We have no food home, you _ go and get some, Tom. A. must B. have to C. can D. will(2)Jim, shall we go and play tennis. Sounds good, but I _ finish my work first. A. must B. can C. may D. need,B,A,例1(温州中考)Is that man Mr Hu?That _ be Mr Hu. Because he has gone to Japan with his wife. A. couldB. cant C. mightD. must答案B解析根据所给语境，本题中因为说Mr Hu. has gone to Japan，所以可以明确判断他去日本还没有回来，对方提到的哪个人就肯定不可能是Mr Hu，故选B。,考题回放,例2(嘉兴中考)May I smoke here?No, you _ only do that in the smoking room.A. can B. needC. mustnt D. couldnt答案A解析A。本题考查情态助动词may引导的疑问句的肯定回答。根据句意，你只可以在吸烟室吸烟，表示允许可以，不是需要或者禁止的意思，故选A。,例3(杭州中考)Where is mom now?Im not sure. She _be in the kitchen.A. shall B. mayC. need D. must答案B解析本题给出语境，问妈妈在那里，对方说我不确定不清楚，所以语气应该是没有很大把握，是不确定的猜测，应该用may be 来表达，故选B。,例4 (湖州中考)Speak louder, please. I _ catch what you are saying.A. mustntB. cantC. needntD. shall not答案B解析本句意为请大声讲，我不能听到你说的话。cant 表示不能够，而不是不许可或者不需要，故选B。,例5(舟山中考)Mum, may I watch TV now?No, you _ finish your homework first.A. mustnt B. mustC. needD. cant答案B解析本题考查情态助动词may引导的疑问句的回答方式，意为你必须首先完成你的家庭作业，故根据所给语境选B。,例6 (盐城中考)The desk is not dirty. You _clean it. A. mustntB. shouldntC. needntD. cant答案C解析本题考查情态动词need(需要)的基本用法。从句意“桌子不脏”可知不需要擦。故选C。,例7 (福州中考)Dad, must I do my homework now?No, you _ play games with friends for a little while. A. wouldB. neednt C. may答案C解析本题考查情态动词may的基本用法。may表许可。从句意“不，你可以和朋友们玩一会儿”可判断C为正确选项。,例8 (三亚中考)Will you stay here for supper? Sorry, I _.Ill have to meet my uncle at the station.A. mustntB. cantC. needntD. dont答案B解析本题考查情态动词can的基本用法。can意为“能够”，从句意“我将去车站接我叔叔”可判断我不能留下来吃晚饭。故选B。,自主检测,()1.Must I return the book right now？ No, you_. A. wouldntB. cant C. neednt D. shouldnt()2.May I borrow your umbrella? Sorry, I _ lend it to you because it is broken. A. cant B. mustnt C. shouldnt D. neednt,C,A,()3.Can you play with a yoyo, Jim? Yes, I _. Its easy. A. must B. can C. need D. may ()4.When the traffic light is red, you_ cross the road. It s very dangerous. A. mustnt B. neednt C. must D. need,B,A,()5.Its nearly six pm, will you have supper here? Sorry, _. I have many things to do. A. I mustntB. I cant C. I needntD. I dont ()6.May I go out to play basketball, Dad? No, You _ finish your homework first. A. must B. may C. couldntD. neednt,B,A,()7.Who is the man over there? Is it Mr Li? No, it_ be him. Mr. Li is much taller. A. cant B. may not C. mustnt D. neednt()8._ you hear me clearly from far away? Sorry, I cant. Say it again, will you? A. May B. Need C. Must D. Can,A,D,()9.Would you like to go swimming with me this afternoon? Id love to. But Im afraid I _. I have too much work to do. A. cant B. mustnt C. needntD. may not()10.Im sorry I didnt win the game. Well, thats OK. You _ win every time. A. mustntB. may not C. cant D. shouldnt,A,C,()11.What do drivers do when the traffic lights turn red? They_stop and wait till the green light. A. mustB. can C. may D. need()12.Look! Someone is cutting a tree on the moon. It_ be true, Granny. Mum says there is no air there. A. cantB. mustnt C. may D. should,A,A,()13.Shall I get one more cake for you, Dad? Thanks, but you _， Ive had enough. A. may notB. must not C. cant D. neednt()14.Will you stay here for supper? Sorry, I _. Ill have to meet my uncle at the station. A.