Unit3-Unit4 情态动词讲解&练习 2025-2026学年外研版八年级英语下册

情态动词should、must、can、need、have to与had better 　　情态动词本身有词义,表示说话人对有关行为或事物的态度和看法,不能独立作谓语,一般和实义动词原形一起构成谓语,并放在实义动词原形前。 情态动词及其用法 例句 should意为“应当”,表示建议或劝告,有“劝说”或“敦促”的含义,否定式为should not/shouldn't。 You should talk to your parents about your feelings. 你应该和你父母谈谈你的感受。 had better意为“最好”,表示劝告或建议,一般不用于疑问句中,否定式为had better not。 You had better not tell Oliver. 你最好不要告诉Oliver。 (1) can表示请求许可或给予许可, could也有此用法,语气比can更委婉; 否定式cannot/can't表示“不能,不可以”,语气弱于must not。 (2) can/could均可表示能力, could是can的过去式,可以表示过去的能力。 一般情况下,以can开头的一般疑问句,肯定回答用can, 否定回答用can't。 —Can I borrow your bike? 我可以借你的自行车吗? —Yes, you can. 是的,你可以。 —No, you can't. 不,你不可以。 Can you type?你会打字吗? When I was young, I could climb any tree in the forest. 年轻时,森林里的树我都能爬上去。 must表示“必须” 否定式must not/mustn't表示“不应该,禁止”,是强有力的劝告或命令。 由must引导的一般疑问句,肯定回答用must,否定回答用needn't/don't have to,表示“不必,没有必要”。 All passengers must wear seat belts. 所有乘客都必须系安全带。 Cars must not park in front of the entrance. 车辆不得停在入口处。 —Must I clean the room this afternoon? 我必须今天下午打扫房间吗? —Yes, you must. 是的,你必须。 —No, you needn't/don't have to. 不,你不必。 have to表示“不得不,必须”,否定式do not/don't have to表示“不必,没有必要”(=needn't)。 You don't have to worry about them any more. 你再也不必为他们发愁了。 need表示“必须,需要”,一般用于否定句和疑问句中,否定式need not/needn't表示“不需要,不必”。一般情况下,以need开头的一般疑问句,肯定回答用must,否定回答用needn't。 —Need I put the umbrella outside? 我需要把雨伞放在外面吗? —Yes, you must. 是的,你必须(放在外面)。 —No, you needn't. 不,你不必(放在外面)。 shall用于第一、三人称的疑问句中时,表示征求对方的意见或提出建议。 Shall I answer the telephone for you? 要我替你接电话吗? Let's begin now, shall we? 咱们现在开始,好吗? 辨析must与have to 区别 例句 must侧重于说话者的主观看法,认为有必要或有义务去做某事;have to侧重于客观需要,含有“不得不,被迫”之意。 You must be back before 10 o'clock. 你必须在10点之前返回。(叮嘱或命令) You have to be back before 10 o'clock because the train is to leave at 10:05.你必须在10点之前返回,因为火车10:05开。(客观需要) must没有人称、时态和数的变化,而have to有。 The old man has to live alone because his son works in another city. 那位老人不得不独自生活,因为他的儿子在另一个城市工作。 注意need还可作行为动词,表示“需要”,有时态、人称和数的变化,常用于need to do sth结构中,用于否定句和疑问句中时需要借助助动词。 You don't need to stay here all the time. 你不必一直待在这里。 一．单项选择 1．—Will you please stay here for the party? —Sorry, I ________. I’ll have to go to an important meeting. A. can’t B. needn’t C. mustn’t D. won’t 2．—What ________ I do when my parents don’t agree with me? —You ________ talk with them and let them know your thoughts. A. needn’t; should B. could; shouldn’t C. can; can’t D. should; can 3．Just like the weather, life ________ be sunny and beautiful all the time. A. can’t B. mustn’t C. needn’t D. wouldn’t 4．—Excuse me, sir. Can I go home now? —No, you ________. Please clean the classroom first. A. can’t B. mustn’t C. needn’t D. shouldn’t 5．—________ you go shopping with me this afternoon?—Sure, I’d love to. A. Can B. Should C. Must D. Need 6．—Dad, must I finish my homework today? —No, you ________. You should go to bed now and finish it tomorrow. A. can’t B. needn’t C. shouldn’t D. mustn’t 7．People ________ wear helmets (头盔) when they ride e-bikes. A. can B. may C. must D. might 8．—________ we take part in the singing activity? —No, you ________. You can decide by yourselves. A. Must, must B. Should, can C. Must, needn’t D. Must, can’t 9．You _________ return the book to the library by Friday, or you _________ pay a fine. A. must; have to B. can; must C. may; will D. should; might 10．—Can we play games here? —Better not. If you ________, please go to the open space there. A. must B. can C. may D. should 11．—________ we go to the concert this weekend? —Good idea! I really want to enjoy the music. A. Shall B. Must C. Need D. Should 12．—Mum, it’s a fine day today. ________ we go on a picnic? —Good idea. A. Shall B. Must C. Should D. Need 13．—When will your flight arrive? I’ll pick you up at the airport. —Thank you, but you ________. I can take a taxi. A. can’t B. mustn’t C. shouldn’t D. don’t have to 14．—Must we arrive at the airport two hours earlier? —No, ________. A. you mustn’t B. you don’t have to C. you must D. you have to 15．—Mom, ________ you go shopping with me this Sunday? —I’m afraid not. I ________ look after your grandma. You can go with your sister. A. can; have to B. can; can C. must; have to D. must; can 16．The alarm went off. You’d better ________ up and go to school. A. got B. get C. to get D. getting 17．—We are free this evening. Shall we go out for a walk? —It’s foggy. We’d better ________. Why ________ a film at home? A. not walk; not watch B. not to walk; not to watch C. not to walk; not watch D. not walk; not to watch 18．You’d better ________ out at night alone. It is dangerous. A. go B. to go C. not go D. not to go 19．—Tom, you look tired. You had better ________ up late at night. —Yes, I ________ go to bed earlier. I’ll make sure to get enough sleep tonight. A. not to stay; must B. not staying; can C. not stay; should D. to not stay; need 20．You ________ her if she ________ you to do so. A. had better not to call; doesn’t allow B. had better not call; won’t allow C. had better not to call; can’t allow D. had better not call; doesn’t allow 21．—Must I stay here and look after the little dog? —No, you ________. A. can’t B. needn’t C. mustn’t D. shouldn’t 22．—Must I return the books the day after tomorrow? —No, you ________. You can ________ them for 15 days. A. mustn’t; keep B. needn’t; borrow C. needn’t; keep D. mustn’t; borrow 二．语法填空 Xi’an is the capital city of Shaanxi province. It lies in 1 north of China. The city’s early history is often connected with Liu Bang, who started the Han Dynasty and made Xi’an his capital. He 2 (give) it the name Chang’an. During the Tang Dynasty, Xi’an achieved its great importance. Korea and Japan followed Xi’an’s example in 3 (build) their ancient capitals. Many things from ancient times can still be found in Xi’an today. The city wall—one of the few city walls still left in China, is a good example. It 4 (go) around the city and is an important cultural site. In central Xi’an there is the Bell Tower—the 5 (large) bell tower remaining in ChinA. The bell was first designed as an emergency alarm to warn of danger, 6 it was very often used to tell people the time. While Xi’an is a city 7 a long history, it is also very much a part of the modern worlD. It is best 8 (know) as a center for software research, development and services. Historically, Xi’an has always been a city of art, industry and business that have placed it far in front of many other 9 (city). Xi’an is a city always remaking 10 (it) and looking forward, all the while keeping the best of the past. 表示“可能性与推测”的常用情态动词 一． 情态动词may/might表示可能性 may/might表示将要发生或正在发生的可能性。此时,might不是may的过去式,它所表示的可能性比may所表示的可能性(现在或将来的可能性)小一些。may不用于表示是否可能的疑问句。 He may not know the answer.他可能不知道答案。 Mike might phone. If he does, could you ask him to ring later? Mike或许会打电话。如果他打电话,你能否让他晚点再打过来? 注意 表示“可能”的常见词possible、possibly、probably、maybe等 单词 例句 possible Is it possible to get tickets for the game? 有没有可能弄到比赛的门票? possibly/ probably It will possibly/probably take us about a week to complete the task. 我们可能需要一星期左右来完成这项任务。 maybe The chair will cost one hundred, maybe two hundred yuan. 这把椅子要花费一百元,或许两百元。 二． 情态动词must、can、could表示推测 单词 用法 must 表示有把握的推测,意为“一定,肯定”,通常只用于肯定句。 can 可表示对现在或将来的推测,意为“会,可能”,往往用于否定句和疑问句。 用于疑问句时,can比could表示的可能性要大;用于否定句时,can't意为“不可能”,表示有把握的否定推测。 could 可表示对现在或将来的推测,意为“会,可能”,可用于肯定句、否定句和疑问句。 You must be tired after the long work. 长时间工作之后,你一定累了。 Can/Could this be true? 这有可能是真的吗? It can't be David because he has gone to Beijing. 不可能是David,因为他去北京了。 一．单项选择 1．—Have you decided where to go for your winter vacation? —Not yet, but we ________ go to Harbin. It’s a good place for vacation. A. can’t B. mustn’t C. should D. may 2．—John isn’t at school today. Do you know why? —He ________ have a bad cold, but I’m not sure about it. A. may B. must C. will D. should 3．—I’m planning to have a trip to Hong Kong for the winter holiday. What about you? —That’s great! We ________ go to my father’s hometown but we haven’t decided yet. A. may B. must C. should D. need 4．—Why is Daniel so happy today? —He ______ win the writing competition. Look at the prize in his hand. A. may B. can C. must D. should 5．—Can you arrive on time for tonight’s meeting? —I’m not sure. The train ________ be late. A. must B. can C. may D. should 6．A hard-working man ________ be a successful man, but a successful man ________ be a hard-working man. A. may not; can B. can’t; may C. may not; must D. can’t; should 7．—What is your brother John doing? —I’m not sure. He ________ be studying in the school library. A. must B. might C. need D. would 8．—Mom, there is a beautiful box on the table. What’s in it? —I’m not sure. It ________ be a gift from your brother. A. must B. might C. can D. will 9．—The winter holiday is coming. Where are you going for a trip? —I ______ go to Harbin, but I’m not sure. A. might B. must C. need D. would 10．—Is there an action movie on show in Town Cinema tonight? —There ______ be one. But you’d better check on the app to make sure. A. must B. will C. can D. might 11．—The paper cutting is pretty lively. Who made it? —It _________ be Amy. None of us except her is able to do it. A. would B. can C. need D. must 12．—Whose is the beautiful handbag on the table? —It ________ be Holly’s. Her name is on it. A. must B. can C. should D. would 13．You ________ be excited. You won the first prize in the dancing competition and you danced with your idol. A. need B. have to C. must D. can’t 14．—Whose book is it? —It ________ be David’s, because his name is on it. A. might B. must C. can’t D. needn’t 15．—Who is knocking at the door? —It ________ be Tom. He said he would come at 3 p.m. A. must B. may C. can’t D. need 16．—Someone is knocking on the door. Who is it? —It ________ be Jenny. She always brings the key with her. A. may B. can’t C. must D. needn’t 17．—I think the souvenir (纪念品) is made in France. I like it so much! —It ________ be from foreign countries. Look! It says “Made in China”. A. must B. mustn’t C. can’t D. could 18．—Look! The man over there is wearing a strange hat. Is he Mr. Smith? —It ________ be him. Mr. Smith has gone to Beijing on business and he won’t be back until next week. A. mustn’t B. can’t C. needn’t D. shouldn’t 19．—Is this bike Lucy’s? —Well, it ________ be Lucy’s. Hers is red, but it is blue. A. can’t B. must C. should D. needn’t 20．—I’m feeling bad because I didn’t do well in the running race. —That’s OK. You _______ win every time. A. can B. may C. can’t D. mustn’t 21．—What’s that smell? —It ________ be something burning, but I’m not sure. A. could B. can’t C. should D. must 22．You ________ drop him and hurt him even more, so don’t move him. A. could B. should C. must D. need 23．—Where is Linda? — I’m not sure. She ________ in the school library. A. could be B. must be C. can’t be D. will be 24．— I’ve taken a white jacket by mistake.   — It ________ be Gina’s. She sometimes wears white. A. must B. should C. need D. could 25．—Lucy, I’ve signed for the box. What’s in it? —I’m not sure. It ___________ be a dress. A. need B. must C. could D. will 二．语法填空 Can you imagine traveling around the world but not taking any planes? Torbjorn Pedersen, a Danish traveler, spent nearly 10 years visiting every country 1 taking any planes. In 2013, he read an article about someone that had visited all the countries. Mr Pedersen realized he could set a record by doing something similar. He made a few 2 (rule): no flying, no visiting home. He hoped that he could live on about $20 a day and spend at least 24 hours 3 (stay) in every country. The first part of his trip was pretty easy and he traveled 4 (happy). But a she moved on, things began to get much 5 (hard). Once he was in a dangerous situation and though he might lose his life. 6 he also had many good experiences. He got a lot of help from people all over the world, 7 he didn’t give upon the halfway. “You might have to try 1,000 closed doors,” he said, “but there is always 8 open door somewhere. Never, ever give up and always believe in 9 (you).” Finally, in May 2023, Mr. Pedersen arrived in Maldives, the last country on his list. In July, Mr. Pedersen 10 (return) to his country. Now, Mr. Pedersen is enjoying his quiet time to think about his trip. After that, he plans to write a book and share what he learned in his travels around the world. 学科网（北京）股份有限公司 $