(
课件网) Unit 7 Teenagers should be allowed to choose their own clothes. （三） 语法加油站 情态动词被动语态 一、核心结构 情态动词的被动语态基本公式： 情态动词 + be + 过去分词（done） 情态动词：can, may, must, should, need （情态用法）, will, would, shall, ought to 等。 be 动词：必须用原形（因情态动词后接动词原形） 过去分词：规则动词加 - ed，不规则动词需记忆 （如 do→done, make→made） 2. may /might（许可、可能） 主动：They may use this tool. （他们可以使用这个工具。） 被动：The tool may be used by them. （这个工具可以被他们使用。） 疑问：May the report be handed in tomorrow （这份报告可以明天提交吗？） 既学既练 1. These math books _____ (might/sell) at the book sale tomorrow. 8. The drawer _____ (can/open) with this key—try it again. can be opened might be sold 3. must /have to（必须、义务） 主动：We must finish the work today. （我们必须今天完成这项工作。） 被动：The work must be finished by us today. （这项工作必须被我们今天完成。） 否定（禁止）：This area mustn't be entered without permission. （未经许可禁止进入该区域。） 既学既练 1.The project _____ (must/finish) before 5 o’clock this afternoon. 2. Students _____ (have to/wear) uniforms on school days, but today is a casual day. must be finished have to be worn 4. should /ought to（应该、建议） 主动：We should protect the environment. （我们应该保护环境。） 被动：The environment should be protected by us. （环境应该被我们保护。） ought to 搭配：The rules ought to be followed. （这些规则应该被遵守。） 既学既练 1. These laws _____ (should/not/break) by anyone in China. 2. The broken window _____ (ought to/repair) as soon as possible to keep the room warm. shouldn’t be broken ought to be repaired 5. need（情态动词：需要，多用于否定 / 疑问） 主动：Tom needn't do the dishes now. （汤姆现在不必洗碗。） 被动：The dishes needn't be done now. （碗现在不必洗。） 注意：need 作实义动词时，被动语态为 “need to be done” Eg: The bedroom needs to be cleaned. 既学既练 1. Your homework _____ (need/not/hand in) today; you have one more day. 2. The lazy boy’s room needs _____ (clean) immediately—it’s too messy. needn’t be handed in to be cleaned 三、特殊用法与注意事项 1.否定形式：直接在情态动词后加 not （如 can→can't, may→may not, must→mustn't） 结构： 情态动词 + not + be + 过去分词 . 2. 疑问形式：将情态动词提前至句首 结构：情态动词 + 主语 + be + 过去分词？ Eg: Can the machine be fixed 三、特殊用法与注意事项 3.无被动的情况：部分情态动词（如 dare 作情态动词时） 较少用于被动，若需表达被动含义，转换为实义动词。 Eg: You dare not be criticized. → You doesn't dare to be criticized. 4.过去分词的正确性：被动语态的核心是 “be + 过去分词”， 需确保过去分词形式正确（如 see→seen，not seeed）。 既学既练 1. _____(敢于) he tell the truth 2. Nobody would _____(dare/ question) the professor’s idea. 3. No one dared _____(talk) about the secret. to talk Dare dare question 四、口诀总结 情态被动不复杂， “情态 + be + done” 记牢它； 否定 not 加情态后，疑问情态提前 ... ...
