Unit2 can could语法详解+专项练习2025-2026学年人教版英语八年级上册

该初中英语单元复习讲义通过分类梳理和对比表格构建了can/could礼貌请求与许可的知识体系，涵盖概念界定、具体用法（请求他人做事与请求许可）、核心考点（Can与Could区别、please位置等），用表格清晰呈现句式结构、语气特点及适用场景，体现知识内在逻辑与重难点分布。 讲义亮点在于分层练习设计与语用能力培养，基础题（填空、匹配问答）巩固基础，提升题（补全对话、句型转换）强化应用，结合“家务请求、借用物品”等居家场景培养语言能力。易错点提醒（如Could答语用can）指导精准，参考答案完整，助力不同层次学生自主复习，也为教师实施分层教学提供支持。

Unit2语法详解+专项练习 用can/could表达礼貌请求与许可 1. 概念界定 Can和Could均为情态动词，本身有一定词义但不能独立作谓语，需与动词原形连用。本单元中二者核心功能为： · 提出礼貌请求：请求他人为自己做某事； · 请求许可：请求他人允许自己做某事。 could是can的过去式形式，但在本单元中不表示过去时间，仅用于增强请求的委婉性。 2. 具体用法拆解 （1）用法一：请求他人做某事（礼貌请求） 指说话人希望对方完成某个动作，是向他人发出的“帮忙请求”。 句式结构 语气特点 适用场景 教材原句示例 Can you (please) + 动词原形 + 其他？ 日常礼貌，语气较随意 熟人、平辈之间（朋友/同学/家人） Can you help me hang up the photos? Could you (please) + 动词原形 + 其他？ 更委婉、正式，礼貌程度更高 对长辈、陌生人，或正式场合 Could you please sweep the floor? 答语分类： · 肯定答语（同意帮忙）： 基础款：Sure./Of course./No problem./Certainly. 进阶款：I’d love to./With pleasure. · 否定答语（拒绝帮忙）： 礼貌款：Sorry, I can’t. + 原因（说明理由避免生硬） 示例：Sorry, I can’t. I have to finish my homework first. （2）用法二：请求他人允许自己做某事（请求许可） 指说话人希望获得对方的同意，去做某件事。 句式结构 语气特点 适用场景 教材原句示例 Can I + 动词原形 + 其他？ 日常场景，语气较直接 熟人之间、非正式场合 Can I put some flowers on the table? Could I + 动词原形 + 其他？ 更委婉，期待礼貌回应 对长辈、陌生人，或需要客气的场景 Could I hang out with my friends after lunch? 答语分类： · 肯定答语（允许）： 基础款：Yes, you can./Of course (you can)./Sure. 进阶款：Go ahead./No problem. · 否定答语（不允许）： 礼貌款：Sorry, you can’t. + 原因 示例：Sorry, you can’t. You have a basketball game tomorrow. 3. 核心考点拆解 （1）Can与Could的核心区别 维度 Can Could 时间含义 表现在/现在的请求/许可 本单元中无过去含义，仅表委婉 语气强度 较直接，礼貌程度一般 更委婉，礼貌程度更高 适用对象 平辈、熟人 长辈、陌生人、正式场合 ⚠️ 易错点：Could I...?的肯定答语用Yes, you can.，而非Yes, you could.，因为could仅表语气，并非过去时。 （2）Please的位置变化 please可在请求句中灵活放置，不改变句意，仅调整停顿和语气： · 句首：Please can you pass the salt?（强调请求） · 句中：Can you please pass the salt?（最常用，日常礼貌） · 句尾：Can you pass the salt, please?（语气更舒缓） （3）否定请求的句式 请求他人不要做某事，结构为： Can/Could you please (not) + 动词原形 + 其他？ 示例： · Can you please not talk loudly?（请你不要大声说话好吗？） · Could you please not open the window?（请你不要开窗好吗？） （4）情态动词的共性特点 1. 后接动词原形，无人称和数的变化： ✅ He can help you.（正确） ❌ He cans help you.（错误） 2. 变否定句直接加not： can not = can’t，could not = couldn’t 示例：I can’t go with you. / She couldn’t finish the work. 3. 变疑问句直接将can/could提至句首： 示例：Can he swim? / Could she borrow your book? 4. 语用场景拓展 结合“居家生活”主题，can/could的常见应用场景： · 家务请求：Could you please take out the rubbish?（请你倒垃圾好吗？） · 借用物品：Can I use your ruler?（我能用你的尺子吗？） · 外出许可：Could I go to the supermarket?（我能去超市吗？） · 寻求帮助：Can you help me fix the bike?（你能帮我修自行车吗？） 专项练习题 （1）基础题：用can/could填空（结合语境选填，10题） 1. ________ you please help me with my math homework? 2. ________ I borrow your umbrella? It’s raining outside. 3. ________ you pass me the milk, please? 4. ________ I watch TV after I finish my homework? 5. ________ you please not play computer games for too long? 6. — ________ I go to the cinema with Tom? — Sorry, you ________. You have to clean your room. 7. — ________ you cook noodles for me? — Sure, I’d love to. 8. — ________ I use your phone to call my mum? — Yes, you ________. Here you are. 9. ________ you please open the door? It’s hot in the room. 10. — ________ you take care of my dog when I’m away? — I’m sorry, I ________. I’m allergic to dogs. （2）基础题：匹配问答（将A栏的请求与B栏的答语匹配，8题） A栏 1. Could you please sweep the floor? 2. Can I put my bag here? 3. Could I borrow your pen? 4. Can you help me wash the clothes? 5. Could you please turn off the TV? 6. Can I go out with my friends? 7. Could you pass me the newspaper? 8. Can you please not smoke here? B栏 A. Sure, here you are. B. Sorry, you can’t. It’s too late. C. OK, I’ll do it right now. D. Of course, no problem. E. Yes, go ahead. F. Sorry, I can’t. I have a cold. G. Sure, I’ll turn it off at once. H. Sorry, I won’t do it again. （3）提升题：选择最佳选项补全对话（10题） 1. A: ________ I use your toilet, Mr Lake? B: Of course you can. Let me show you the way. A. Can B. Must C. Should 2. A: Could you give me a ride to town now? B: ________ I have to go to the hospital. A. Sure. B. Sorry, I can’t. C. Yes, I could. 3. A: Can I stay until eleven? B: ________ if you are careful with your time. A. No, you can’t B. Yes, you can C. Sorry, you couldn’t 4. A: Could I use your computer? B: Yes, ________. A. you could B. you can C. I can 5. A: Can you help me hang up the photos? B: ________. A. No problem B. Yes, I do C. No, I’m not 6. A: Could you please ________ the dishes? B: Sure, I’ll do it after dinner. A. wash B. washing C. washed 7. A: Can I go to the movies tonight? B: No, you can’t. ________ you have a test tomorrow. A. So B. Because C. But 8. A: Could you please not ________ loud music? B: Sorry, I’ll turn it down. A. play B. playing C. plays 9. A: ________ I borrow your bike? B: Sorry, it’s broken. A. Need B. Must C. Could 10. A: Can you please take out the rubbish? B: ________. I’m busy with my homework. A. Of course B. Sorry, I can’t C. Yes, I could （4）提升题：句型转换（8题） 1. Can you please open the door?（改为否定句） _________________________________________________________________ 2. Could I go shopping with my sister?（作肯定回答） _________________________________________________________________ 3. He can help me with my English.（改为一般疑问句） _________________________________________________________________ 4. She could use your dictionary.（改为否定句） _________________________________________________________________ 5. Can we play basketball in the park?（作否定回答并说明原因） _________________________________________________________________ 6. Could you please clean your room?（改为同义句，将please放句首） _________________________________________________________________ 7. I can go to the park with you.（对划线部分提问） _________________________________________________________________ 8. They can finish the work in an hour.（对划线部分提问） _________________________________________________________________ 参考答案 （1）基础题：用can/could填空 1. Could 2. Could/Can 3. Can/Could 4. Can/Could 5. Could 6. Can; can’t 7. Could/Can 8. Could; can 9. Can/Could 10. Could; can’t （2）基础题：匹配问答 1-C 2-E 3-A 4-F 5-G 6-B 7-A 8-H （3）提升题：选择最佳选项补全对话 1-A 2-B 3-B 4-B 5-A 6-A 7-B 8-A 9-C 10-B （4）提升题：句型转换 1. Can you please not open the door? 2. Yes, you can. / Of course (you can). 3. Can he help you with your English? 4. She couldn’t use your dictionary. 5. Sorry, you can’t. It’s raining outside.（原因合理即可） 6. Please could you clean your room? 7. What can you do with me? 8. How soon can they finish the work? ( 1 ) 学科网（北京）股份有限公司 $