Unit 9 情态动词详解与训练 2024-2025学年人教版英语八年级上册

A friend in need is a friend indeed.患难见真情。 情态动词 情态动词本身有一定的意义,但不能独立作谓语,要和动词原形一起构成谓语,表说话人的语气和态度。它没有人称和数的变化(have to除外,其第三人称单数为has to)。 (1)情态动词的基本用法 情态 动词 用法 例句 can 1)表示能力,相当于be able to,有“能”“会”的意思。 2)表示可能性,有“会”“可能” 的意思,多用在否定或疑问句中。 3)表示请求许可,相当于may。 The bird can speak three languages. —Can it be true?—No, it can't be true. Can I borrow the book from Tom? could 1)could是can的过去式,表示过去的能力需用could。 2)但表可能性和请求许可时could也可以用于现在时,表达委婉或客气的语气。 He said he could go to the bench last year. Could I ask you for help? I think he couldn't be that silly. may 1)表示请求许可,否定回答用can't/mustn't。 2)表示可能性,一般用于肯定句。 3)表示祝愿,常置于句首。 —May I borrow your computer? —No,you can't/mustn't. You may be correct, but I am not sure. May you succeed! might might是may的过去式,表达请求许可、可能性,语气比may更委婉,表示的可能性比may更低。 Might I eat something here? He is away from work. He might be ill. must 1)表示必要性,否定回答用needn't。 2)表示可能性,语气肯定,只用于肯定句,可译成“一定”。 3)mustn't表示禁止,可译成“不准”。 4)表示意图或意愿,语气较强,可译成“一定”。 —Must I get to the bank at six? —No, you needn't. The door is still open. He must be in the office. Tom, you mustn't play with dog. It's too dangerous. I must catch up with my classmates. need 1)need表示必要性,常用在否定和疑问句中,肯定回答用must。 2)need还可以用作行为动词。 —Need we try a second time? —Yes, you must. Does he need any help? will 1)用于第二人称的疑问句,表示说话人征求对方意见。 2)用于各人称,表示意愿。 3)表示习惯或规律。 Will you please read it again? Give him a hand, will you? We will do anything for you. Dad will walk around the room before he decides to do something important. would would是will的过去式,但可以用于现在时表达委婉或客气的语气。 Would you please bring your football here tomorrow? He would share his interesting stories with us when we were at high school. shall shall用于第一、三人称,表示说话人征求对方意见。 Shall we go on or just stop here? Shall he come in? should should译为“应该”,表示劝告、建议、义务、责任。 You should put the boxes this way. I think you should communicate with your parents about this matter. You should take it seriously, or you will lose. have to 表示客观需要,译为“必须,不得不”。have to有时态、人称和数的变化,第三人称单数为has to,过去式为had to。 It's raining hard outside. I have to stay at home. had better 表示劝告或建议,译为“最好”。 You had better (not) lend the book to him. (2)常见情态动词词义辨析 ①can与be able to can 表示“能力”时两者用法相同,can只有一般现在时和一般过去时(could)。 Jim couldn't speak Japanese last year, but now he can. be able to be able to用于现在时、过去时和将来时。 We will be able to come back next week. ②must与have/has to must 表示主观看法,意为“必须”。 We must study hard at school. have/ has to 强调客观需要,意为“必须,不得不”。 We will have to ask Jack instead. ③can't与mustn't can't 表示否定推测,意为“不可能”。 It can't be Miss Wang. She has gone to Germany. mustn't 意为“禁止,不许”,不能表示推测,而must用于肯定句中表示推测,意为“一定”。 You mustn't take photos here. ④may be与maybe may be may为情态动词,意为“也许,可能”,后接动词原形be,用于句中,作谓语。 She may be in the office. maybe maybe为副词,意为“大概,也许”,相当于perhaps,用于句首,作状语。 Maybe she is in the office. 一、单项选择题 1. You _ be careful when crossing the road. A. must B. can C. may D. might 2. —Must I finish my homework today?—No, you _. You can do it tomorrow. A. mustn't B. needn't C. can't D. shouldn't 3. He _ know the answer, but I'm not sure. A. may B. must C. can D. should 4. You _ smoke in the hospital. A. mustn't B. needn't C. can't D. shouldn't 5. —Can I borrow your bike?—Sure. But you _ return it on time. A. can B. may C. must D. might 6. —_ I borrow your dictionary?—Sure. Here you are. A. Must B. Need C. May D. Should 7. You _ be late for school again. A. mustn't B. needn't C. can't D. shouldn't 8. —Must I clean the room now?—No, you _. A. mustn't B. needn't C. can't D. shouldn't 9. He _ know the answer. He looks so confident. A. must B. may C. can D. should 10. You _ drive after drinking. A. mustn't B. needn't C. can't D. shouldn't 参考答案:ABAAC CABAA 二、用适当的情态动词填空 1. You _ study hard if you want to get good grades. 答案:must。 2. She _ be at home. I just saw her go out. 答案:can't。 3. —_ I use your pen?—Sure. Here you are. 答案:May。 4. We _ respect our parents and teachers. 答案:should。 5. You _ play football in the street. It's very dangerous. 答案:mustn't。 6. You _ hand in your homework on time. 答案:must。 7. She _ be very tired after such a long journey. 答案:must。 8. We _ listen to the teacher carefully in class. 答案:should。 9. _ you please pass me the book? 答案:Could/Can/Will/Would。 10. He _ not come to the party. He is very busy. 答案:may。 1 学科网(北京)股份有限公司 $$