Unit4语法讲解及习题：疑问词+to-infinitive & must与have to的用法 2025-2026学年译林版八年级英语下册

该初中英语单元知识清单系统梳理了译林八下Unit4核心语法，涵盖“疑问词+to-infinitive”和“must与have to的用法”两大范畴，搭建了从结构解析、功能示例到转换规则的递进式学习支架，配套多样化习题巩固应用。 清单通过表格对比（如must与have to的强调重点、否定形式等维度）和“特别注意”标注（如why不与to-infinitive连用）构建知识体系，体现语言能力培养。设计分层习题（填空、选择、改写句子等）和短文语境应用，参考答案解析助力思维品质提升，既方便学生自主学习，也为教师教学提供精准支持。

译林英语八下Unit4语法讲解及习题 疑问词+to-infinitive & must与have to的用法 一、语法讲解 1. 核心语法点1：疑问词+to-infinitive（疑问词+动词不定式） 疑问词（what, which, who, where, when, how, why）可以与动词不定式（to + 动词原形）结合，在句子中充当主语、宾语、表语等成分，用来表达“要做什么”“怎么做”等含义。 （1）结构与用法 结构 功能 例句 疑问词 + to do 作动词宾语（常见于decide, know, wonder, forget等动词后） Millie has decided what to read.（米莉已经决定要读什么了。） I don't know how to write the book review.（我不知道如何写书评。） 疑问词 + to do 作形容词宾语（常见于sure, clear等形容词后） Are you clear when to meet at the Book Club tomorrow?（你清楚明天读书会什么时候见面吗？） 疑问词 + 名词 + to do 当疑问词是what, which, how many等时，可接名词 You can decide how many books to take with you.（你可以决定要带多少本书。） 特别注意： · 所有疑问词都可以用于这个结构，但why除外，why不与to-infinitive连用。 · 这个结构可以转换为宾语从句，例如：I don't know what to do. = I don't know what I should do. 2. 核心语法点2：must 与 have to 的区别 两者都表示“必须”，但强调的重点和使用场景不同。 维度 must have to 强调重点 强调说话人的主观看法或强烈建议，认为某事有必要做。 强调客观情况或规则、义务迫使某人必须做某事。 否定形式 mustn't：表示“禁止，不准”，语气强烈。 don't/doesn't/didn't have to：表示“不必，不需要”，语气较委婉。 时态变化 只有现在时一种形式，过去时常用had to代替。 有多种时态变化：have to / has to / had to / will have to / have got to。 例句 I must check my spelling and grammar.（我必须检查我的拼写和语法。 强调自己觉得有必要。） You mustn't give away the ending.（你不准剧透结局。 禁止做某事。） I have to hand in the book review on Friday.（我必须周五交书评。 因为规定或要求不得不做。） You don't have to love the book.（你不必喜欢这本书。 表示没有必要。） 二、语法习题 （一）用疑问词+to-infinitive 结构填空 1. Millie has decided ___________ (read) for the Reading Month. 2. It isn't always easy to know ___________ (choose) a book. 3. You'll know ___________ (read) pages each day if you have a plan. 4. Talk to your classmates if you're not sure ___________ (write) about your book. 5. You can ask me ___________ (write) the book review. 6. I'll put up a timetable so you know ___________ (speak) to me. 7. We've decided ___________ (read) first. 8. Mr Wu didn't say ___________ (hand in) the book review. 9. Do you know ___________ (create) a mind map on the computer? 10. We're still not sure ___________ (meet). （二）用 must, mustn't 或 (don't/doesn't/didn't) have to 填空 1. You ___________ follow the library rules while you're here. 2. You ___________ remember to take care of the books. 3. You ___________ write in the books or take out any pages. 4. You ___________ be very quiet in the library. 5. You ___________ bring any food or drinks into the library. 6. You ___________ stay in the library to enjoy the books. You can take them home. 7. I ___________ hand in my book review on Friday. It's a school rule. 8. I ___________ give away the ending of the story. It's a spoiler. 9. You ___________ love the book, but you ___________ give your reasons for your opinion. 10. Gulliver ___________ run away because the tiny men were kind to him. （三）单项选择 1. —I don't know ___________ to start reading this book. —You can begin with the first chapter. A. what B. how C. when D. where 2. He hasn't decided ___________ book to choose for his report. A. which B. what C. how D. who 3. You ___________ talk loudly in the library. It's not allowed. A. don't have to B. have to C. mustn't D. must 4. I ___________ finish my homework tonight because I have a test tomorrow. A. must B. mustn't C. don't have to D. have to 5. She ___________ go to school today because she's sick. A. must B. mustn't C. doesn't have to D. has to （四）按要求改写句子 1. I don't know what I should read.（用疑问词+to-infinitive改写） _____________________________________________________________________ 2. You must not speak in the library.（改为同义句，用have to） _____________________________________________________________________ 3. He has to leave early because he has a meeting.（改为否定句） _____________________________________________________________________ 4. She is wondering where she can find the book.（用疑问词+to-infinitive改写） _____________________________________________________________________ 5. I must check my grammar.（改为一般疑问句） _____________________________________________________________________ （五）短文填空 A. 用疑问词+to-infinitive Millie: I've decided (1) ___________ (read) Gulliver's Travels. But I'm not sure (2) ___________ (start). Simon: You can start with the first part. Do you know (3) ___________ (find) a summary online? Millie: No, but I can ask Mr Wu (4) ___________ (help) me. Simon: Good idea! He'll tell you (5) ___________ (get) the best resources. B. 用 must, mustn't 或 don't have to Welcome to our Reading Month! You (1) ___________ (must) read at least one book. You (2) ___________ (mustn't) read comic books; you (3) ___________ (have to) choose a classic or a novel. You (4) ___________ (don't have to) finish it in one week, but you (5) ___________ (must) hand in your book review by the end of the month. 三、参考答案及解析 （一）用疑问词+to-infinitive 结构填空 1. what to read 2. which book to choose 3. how many pages to read 4. what to write 5. how to write 6. when to speak 7. what to read 8. when to hand in 9. how to create 10. when to meet （二）用 must, mustn't 或 (don't/doesn't/didn't) have to 填空 1. must（图书馆规定，必须遵守） 2. must（必须记得爱护书籍） 3. mustn't（禁止在书上写字或撕页） 4. must（必须保持安静） 5. mustn't（禁止带食物和饮料） 6. don't have to（不必待在图书馆，可以带回家看） 7. have to（学校规定必须周五交） 8. mustn't（禁止剧透） 9. don't have to; must（不必喜欢，但必须给出理由） 10. didn't have to（不必逃跑，因为小人很友善） （三）单项选择 1. D（从答语“从第一章开始”可知，问的是“从哪里开始”） 2. A（在多本书中选择一本，用which） 3. C（图书馆禁止大声说话，用mustn't） 4. D（因为明天有考试，客观上必须完成作业，用have to） 5. C（生病了，所以不必去上学，用doesn't have to） （四）按要求改写句子 1. I don't know what to read.（宾语从句简化为疑问词+to-infinitive） 2. You have to be quiet in the library.（mustn't talk = have to be quiet） 3. He doesn't have to leave early because he has a meeting.（have to的否定形式是don't have to） 4. She is wondering where to find the book.（宾语从句简化为疑问词+to-infinitive） 5. Must I check my grammar?（must的一般疑问句，直接将must提前） （五）短文填空 A. 用疑问词+to-infinitive 1. what to read 2. where to start 3. how to find 4. how to help / what to do to help 5. where to get B. 用 must, mustn't 或 don't have to 1. must 2. mustn't 3. have to 4. don't have to 5. must ( 1 ) 学科网（北京）股份有限公司 $