【弯道超车】Unit 3 Pets 核心语法之情态动词-2025年牛津上海版（试用本）九年级英语上册精讲精练 (含答案解析)

/ 让学习更有效 新课备课备考 | 英语学科 2025年牛津上海版（试用本）九年级英语上册精讲精练 Unit 3 Pets 核心语法：情态动词 一、情态动词基本概念 情态动词是用来表达说话人态度、观点或判断的助动词，具有以下特点： 后接动词原形 无人称和数的变化 不能单独作谓语 没有时态变化（除can/could, will/would等） 二、常见情态动词分类表 功能 情态动词 基本含义 否定形式 能力 can/could 能够/可以 can't/couldn't 许可 may/might/can/could 可以/允许 may not/might not 义务 must/have to/should/ought to 必须/应该 mustn't/don't have to 推测 must/may/might/could/can't 可能/肯定 may not/might not 意愿 will/would/shall 愿意/将要 won't/wouldn't 三、核心情态动词详解 1. can/could 用法 例句 说明 能力 I can swim. She could dance at 5. could表过去能力 请求 Can/Could you help me could更礼貌 许可 You can go now. 口语常用 可能性 It could rain tonight. 可能性较小 注意： can表示理论可能性，could表示更小的可能性 回答Could...问句时用can：Could I... Yes, you can. 2. may/might 用法 例句 说明 许可 May I borrow your pen 正式场合 可能性 She may be late. It might snow. might可能性更小 建议 You might try this method. 委婉建议 区别： may not表示"不允许" might not表示"可能不" 3. must/have to 用法 例句 区别 义务 You must wear a seatbelt. 主观要求 推测 He must be at home. 肯定推测 必须 I have to work today. 客观要求 否定形式： mustn't表示"禁止"（You mustn't smoke here.） don't have to表示"不必"（You don't have to come.） 4. should/ought to 用法 例句 区别 建议 You should see a doctor. 常用 义务 We ought to protect nature. 语气更强 推测 They should arrive soon. 合理推测 否定形式：shouldn't/ought not to 四、情态动词表推测 确信程度 情态动词 例句 时间指向 100%肯定 must She must be tired. 现在/一般情况 80%可能 may It may rain later. 现在/将来 50%可能 might/could He might be sleeping. 现在/将来 不可能 can't That can't be true. 现在/一般情况 注意： 对过去推测：情态动词 + have + 过去分词 She must have left.（她肯定已经离开了） 五、易错点突破 can vs. be able to can表能力或许可 be able to强调通过努力获得的能力，可用于各种时态 After training, I was able to swim. must与have to的区别 must have to 主观要求 客观要求 必须做 不得不做 回答may/might问句 问：May I... 答：Yes, you can./No, you can't.（不用may回答） 六、记忆口诀 "情态动词很重要，原形动词后面靠； can表能力或许可，may表允许更礼貌； must强调必须做，should建议要记牢； 推测用法分强弱，语境判断不可少！" 1．Polluted air and water _____ kill plants, animals, and even people. A．can B．can't C．should D．shouldn't 2．—Mum, will you buy me a new iPad after the Entrance Examination —I'm afraid I _____, dear. We are short of money now. A．mustn't B．can't C．shouldn't D．needn't 3．—You don't have to take a raincoat. It isn't going to rain. —Well， I am not sure. It _____ do. A．must B．need C．may D．would 4．— Could I look at your picture — Yes, of course you _____. A．could B．can C．will D．would 5．Nowadays all passengers go through safety check before take a train. A．can B．may C．must D．will 6．— Mom, what's in the box — I am not sure. It _____ be a present f ... ...