Unit 2 语法易错+巩固练习（导学案）新四年级英语暑假自学课（外研版三起·新教材）

外研版三起新四年级暑假自学课 Unit 2 语法易错+巩固练习 语法易错01 语法点拨 一、情态动词的特点： (1) can和may后面接动词原形 (2) 没有人称和数的变化 (3) 否定形式: can/may+not+动词原形 二、常见情态动词的用法： 1. can (1)能够，会(表能力)； (2)可以(表请求、允许，此时与may意思相近，语气更委婉客气)； (3)可能(表可能性，用于客观的推测)。 (4) 教材原句：Can you tidy your room first? 你能先整理房间吗？ 2.may (1)可以(表示请求、许可)； (2)可能(表示可能性，表示不太有把握的推测)。 (3)教材原句：May I help you wash the dishes, Mum? 妈妈，我可以帮你洗碗吗？ 含情态动词can与may的句型结构 一般疑问句 Can/May+主语+动词原形(+其他)? 肯定回答 Yes,主语+can. Yes,主语+may./Sure./OK./Yes, please. 否定回答 No, 主语 + can't. No,主语 +may not./No,主语+ can't.(大多口语上用) No,主语+mustn't.(具有强烈禁止的意思) No, you'd better not. 例句 Can you sing? —Yes, I can. —No, I can't. May I go out? —Yes, you may./OK. —No, you can't./ No, you mustn't. 知识演练 一、选择最佳答案，将序号填在括号内。 ( ) 1. —Can you speak English? —______ A. Yes, I am. B. Yes, I can. C. No, I don't. ( ) 2. —May I use your ruler? —______ A. Yes, please. B. Yes, you do. C. No, I can't. ( ) 3. You ______ run on the stairs. It's not safe. A. can B. may C. mustn't ( ) 4. ______ you tidy your desk for me? A. Do B. Can C. Are ( ) 5. —May I watch TV now? —No, you ______. You must finish your homework first. A. may not B. can't C. aren't ( ) 6. Lily ______ dance, but she ______ sing very well. A. can't; can B. can; can't C. don't; do 二、按要求改写句子 1. I can clean my room.（改为一般疑问句，并作肯定回答） — ______ ______ clean your room? — ______, ______ ______. 2. She can wash the dishes.（改为否定句） She ______ ______ the dishes. 3. May I open the window?（作否定回答，语气表禁止） ______, ______ ______. 4. They can play basketball.（改为一般疑问句，并作否定回答） — ______ ______ play basketball? — ______, ______ ______. 5. May I sit here?（改为同义问句） ______ ______ sit here? 语法易错02 语法点拨 need和must的用法 1. 基本含义 need 实义动词，意思：需要 2. 句型：主语 + need to + 动词原形. 某人需要做某事 结构拆解：need to 后面必须接动词原形。 例句：I need to clean the floor. 我需要打扫地板。 I need to tidy my room. 我需要整理我的房间。 She needs to wash the dishes. 她需要洗碗。 3. 人称变化 ① 主语是I / you / we / they：用 need to do I need to help. 我需要帮忙。 ② 主语是he /she/it（单数第三人称）：用 needs to do He needs to make the bed. 他需要铺床。 4. 否定形式（基础考点） ① 主语 + don’t /doesn’t + need to + 动词原形 I don’t need to sweep the floor. 我不需要扫地。 She doesn’t need to clean the desk. 她不需要擦桌子。 5. 一般疑问句 Do / Does + 主语 + need to + 动词原形？ — Do you need to help? 你需要帮忙吗？ — Yes, I do. / No, I don’t. 5. must表示“必须”，强调义务、命令。 例: You must follow the rules. 你必须遵守规则。 还可表示有把握的推测。 例:The door is locked, so he must be out. 门是锁着的，所以他一定是出去了。 知识演练 一、选用方框内短语填空，每词限用一次。need to needs to must 1.We ______ keep our classroom clean. 2.My sister ______ read books every evening. 3.I ______ finish my homework before watching TV. 4.You ______ listen to the teacher carefully in class. 5.The cat ______ eat some food now. 二、选出最佳答案，将序号填入括号内。 ( ) 1. He ______ clean his room today. A. need to B. needs to C. needs ( ) 2. — ______ you need to go now? — Yes, I do. A. Do B. Does C. Are ( ) 3. Lily ______ need to water the flowers. A. don’t B. doesn’t C. isn’t ( ) 4. You ______ obey the school rules. It’s our duty. A. need B. must C. can ( ) 5. The light is on. He ______ be at home. A. must B. need C. can’t ( ) 6. My brother ______ need to do sports. A. don’t B. doesn’t C. not 重难点特训 一、单项选择，选择最佳答案，将序号填在括号内。 ( ) 1. — Can you sing songs?— ______ A. Yes, I am. B. Yes, I can. C. No, I don't. ( ) 2. — May I drink some water? — ______ A. Yes, please. B. Yes, you do. C. No, I can't. ( ) 3. You ______ play with fire. It's very dangerous. A. can B. may C. mustn't ( ) 4. ______ you help me carry the bag? A. Do B. Can C. Are ( ) 5. — May I go outside to play?— No, you ______. You have to finish homework first. A. aren't B. can't C. may ( ) 6. Tom ______ swim, but he ______ skate well. A. can't; can B. can; can't C. don't; do ( ) 7. She ______ make her bed every day. A. need to B. needs to C. needs ( ) 8. — ______ you need to go home now?— Yes, I do. A. Do B. Does C. Are ( ) 9. Mike ______ need to water the flowers. A. don’t B. doesn’t C. isn’t ( ) 10. Everyone ______ keep quiet in the library. A. need B. must C. can ( ) 11. The door is closed. He ______ be at home. A. must B. need C. can’t ( ) 12. My grandpa ______ need to do heavy work. A. don’t B. doesn’t C. not 二、按要求改写句子 1. I can tidy my room.（改为一般疑问句，并作肯定回答） — ______ ______ tidy your room? — ______, ______ ______. 2. He can wash the dishes.（改为否定句） He ______ ______ the dishes. 3. May I come in?（作否定回答，表强烈禁止） — ______, ______ ______. 4. We can play football.（改为一般疑问句，并作否定回答） — ______ ______ play football? — ______, ______ ______. 5. I need to sweep the floor.（改为否定句） I ______ ______ ______ sweep the floor. 6. She needs to wash clothes.（改为一般疑问句，并作肯定回答） — ______ she ______ ______ wash clothes? — Yes, ______ ______. 7. They need to help others.（改为否定句） They ______ ______ ______ help others. 三、选词填空（can /may/need to /needs to /must） 1.It ______ rain this afternoon. Take an umbrella. 2.— ______ I use your pencil? — Sure. 3.My little sister ______ draw nice pictures. 4.______ you help me, please? 5.We ______ follow the school rules. 6.My mother ______ clean the room every morning. 7.I ______ finish my homework first. 8.You ______ listen carefully in class. 9.The bird ______ find some food. 四、请选择合适的选项补全短文。 Today is Sunday. After breakfast, my parents go outside to do some shopping. I stay at home. I think I 1.________ (A. can /B. can't) do some chores. I write a to-do list. The floor is 2.________ (A. dirty /B. clean), so I sweep it first. After that, I need 3.________ (A. to / B. for) take out the rubbish in the living room. Then I go to the yard. I cut the grass and see some eggs. I collect them. The rabbit is hungry. I must 4.________ (A. feel / B. feed) the rabbit. It is very cute. After doing these, I am a little tired. Then I go to the bedroom and have a rest. My parents come back. They are very happy to see a clean house and say “5.________ (A. Good job /B. Goodbye)" to me. 参考答案与解析 语法易错题答案01 一、单项选择 1.答案：B 解析：以 Can 引导的一般疑问句，答语必须用 can 呼应。A 用 be 动词、C 用助动词，均错误。 2.答案：A 解析：May I...? 表请求许可，肯定回答常用 Yes, please./Sure./OK。 3.答案：C 解析：mustn't 表示禁止、不准，句意：不准在楼梯上奔跑，很危险。can/may 表示 “可以”，不符合语境。 4.答案：B 解析：句中出现动词原形 tidy，情态动词 Can 后接动词原形，用于请求帮忙。 5.答案：B 解析：口语中回答 May I...? 的否定形式多用 can't；aren't 不能搭配情态问句。 6.答案：A 解析：but 表转折，前后语义相反。句意：莉莉不会跳舞，但是她唱歌很好。 二、按要求改写句子 1.Can you；Yes, I can. 解析：含 can 的陈述句变一般疑问句，直接将 can 提前，主语 I 改为 you；肯定回答遵循问句格式。 2.can't wash 解析：can 的否定形式为 can not (can't)，后接动词原形。 3.No, you mustn't. 解析：题干要求表强烈禁止，用 mustn't。 4.Can they；No, they can't. 解析：can 提前构成疑问句，主语不变；否定回答用 No, 主语 + can't。 5.Can I 解析：May I...?（请求许可）和 Can I...? 为同义句型，可以互换。 语法易错题答案02 一、选用方框内短语填空（need to /needs to /must） 1.must 解析：must 强调义务、规定，句意：我们必须保持教室整洁。 2.needs to 解析：主语 My sister 是第三人称单数，实义动词 need 变为 needs to do。 3.need to 解析：主语为 I，用原形 need to do，表示 “需要做某事”。 4.must 解析：课堂认真听讲是规定，用 must（必须）。 5.needs to 解析：主语 The cat 是第三人称单数，用 needs to。 二、单项选择 1.答案：B 解析：主语 He 为三单，固定搭配 needs to + 动词原形。 2.答案：A 解析：need 是实义动词，变疑问句要借助助动词；主语 you，用 Do。 3.答案：B 解析：主语 Lily 是三单，实义动词 need 的否定形式用 doesn't need to。 4.答案：B 解析：遵守校规是义务，must 表示 “必须”。 5.答案：A 解析：must 用于有把握的肯定推测，句意：灯亮着，他一定在家。 6.答案：B 解析：主语 My brother 是三单，否定形式用 doesn't。 重难点特训 一、单项选择 1.B 解析：Can 问句，用 can 回答。 2.A 解析：May I 请求句式，肯定回答用 Yes, please. 3.C 解析：mustn't 表示禁止玩火。 4.B 解析：Can 用于请求他人帮忙，后接动词原形。 5.B 解析：口语中 May I...? 否定回答常用 can't。 6.A 解析：but 表转折，前后含义相反。 7.B 解析：主语 she 为三单，用 needs to do。 8.A 解析：主语 you，实义动词 need 提问用助动词 Do。 9.B 解析：主语 Mike 三单，否定用 doesn't。 10.B 解析：图书馆保持安静是规则，用 must（必须）。 11.C 解析：门是关着的，推测他不在家，用 can't（一定不）。 12.B 解析：主语 grandpa 三单，实义动词否定用 doesn't。 二、按要求改写句子 1.Can you；Yes, I can. 解析：can 提前变疑问，人称对应转换，肯定回答统一格式。 2.can't wash 解析：can 否定式 can't + 动词原形。 3.No, you mustn't. 解析：强烈禁止，用 mustn't。 4.Can you；No, we can't. 解析：主语 we 对应问句 you，否定回答用 can't。 5.don't need to 解析：主语 I，实义动词 need 否定用 don't need to + 动词原形。 6.Does; need to；she does 解析：主语 she 三单，疑问句句首用 Does，动词变回原形 need；肯定回答用助动词 does。 7.don't need to 解析：主语 They，否定形式用 don't need to。 三、选词填空（can /may/need to /needs to /must） 1.may 解析：表不太确定的推测：今天下午可能下雨。 2.May 解析：表请求许可：我可以用你的铅笔吗？ 3.can 解析：表能力：我的妹妹会画好看的画。 4.Can 解析：表委婉请求帮忙。 5.must 解析：遵守规则，表义务 “必须”。 6.needs to 解析：主语 my mother 三单，需要做某事。 7.need to 解析：主语 I，需要完成作业。 8.must 解析：课堂要求，必须认真听讲。 9.needs to 解析：主语 the bird 三单，需要觅食。 四、短文选词填空 1.A (can) 解析：句意：我觉得我可以做家务，can 表示能力。 2.A (dirty) 解析：后文 “扫地” 说明地面是脏的。 3.A (to) 解析：固定搭配 need to do sth. 需要做某事。 4.B (feed) 解析：兔子饿了，所以必须喂养兔子；feel 意为 “感觉”，不符合句意。 5.A (Good job) 解析：父母看到干净的家，夸赞 “做得好”；Goodbye 是再见，不符合语境。 2 / 2 学科网（北京）股份有限公司 学科网（北京）股份有限公司 $