Unit5 Grammar_动词不定式讲义 -2025-2026学年译林版（2024）八年级英语上册

八年级上册译林版英语讲义：Unit 5 Grammar (动词不定式) 学习目标 1. 理解动词不定式的概念、构成及其在句中的多种功能。 1. 掌握动词不定式作主语、宾语、表语、定语、状语和宾语补足语的用法。 1. 熟悉动词不定式的否定形式、疑问形式以及带to和不带to的动词不定式的使用场景。 1. 通过多样化的练习，巩固所学知识，提升在实际语境中运用动词不定式的能力。 知识点详解 动词不定式（Infinitive）是动词的一种非谓语形式，由“to + 动词原形”构成，也可以是不带to的动词原形。它在句中不能独立作谓语，但具有动词的特点，可以带宾语和状语，同时又具有名词、形容词和副词的特点，可以在句中充当多种成分。 一、动词不定式的构成 · 基本形式：to + 动词原形 (to do) · 否定形式：not to + 动词原形 (not to do) · 疑问形式：疑问词 + to + 动词原形 (how to do, what to do) 二、动词不定式的句法功能 动词不定式在句中可以作主语、宾语、表语、定语、状语和宾语补足语。 1. 作主语 · 位置：通常放在句首，或用it作形式主语。 · 例句： · To learn English is important. (学英语很重要。) · It is important to learn English. (学英语很重要。) 2. 作宾语 · 位置：跟在某些动词后面作宾语，或用it作形式宾语。 · 常跟不定式作宾语的动词：want, hope, wish, decide, plan, agree, learn, manage, promise, refuse, pretend, offer, expect, ask, choose, fail, seem, appear 等。 · 例句： · I want to go home. (我想回家。) · He decided to study abroad. (他决定出国留学。) · I find it difficult to understand him. (我发现理解他很难。) 3. 作表语 · 位置：在系动词 (be) 之后，说明主语的内容。 · 例句： · My dream is to travel around the world. (我的梦想是环游世界。) · His job is to teach English. (他的工作是教英语。) 4. 作定语 · 位置：放在被修饰的名词或代词之后。 · 特点：不定式所修饰的名词或代词通常是不定式动作的承受者。 · 例句： · I have a lot of homework to do. (我有很多作业要做。) · He is the first one to arrive. (他是第一个到达的人。) 5. 作状语 · 表示目的：为了…… (to do) · 例句：He works hard to pass the exam. (他努力学习为了通过考试。) · 表示结果：结果是…… (to do) · 例句：He woke up to find himself famous. (他醒来发现自己出名了。) · 表示原因：因为…… (to be + adj. + to do) · 例句：I am happy to see you. (我很高兴见到你。) 6. 作宾语补足语 · 位置：在“动词 + 宾语 + 动词不定式”结构中。 · 常跟不定式作宾语补足语的动词： · 带to的不定式：ask, tell, advise, allow, encourage, invite, order, persuade, teach, want, wish, expect, get, cause, force, remind 等。 · 例句：I asked him to help me. (我请他帮助我。) · 不带to的不定式 (感官动词和使役动词)：see, watch, hear, feel, notice, make, let, have 等。 · 例句：I saw him play basketball. (我看见他打篮球。) · My mother made me do my homework. (我妈妈让我做作业。) 三、不带to的动词不定式 (Bare Infinitive) · 使用场景： · 在使役动词 (make, let, have) 之后。 · 例句：Let me help you. (让我帮你。) · 在感官动词 (see, watch, hear, listen to, feel, notice) 之后。 · 例句：I heard her sing a song. (我听到她唱歌。) · 在情态动词 (can, may, must, should, will, would, shall, need, dare) 之后。 · 例句：You must study hard. (你必须努力学习。) · 在had better (最好), would rather (宁愿) 之后。 · 例句：You had better go now. (你最好现在就走。) 四、动词不定式与动名词的区别 · 总结表格： 特点 动词不定式(todo) 动名词(doing) 侧重 目的、将来、一次性动作 动作本身、习惯、已发生动作 作主语 常用it作形式主语 可直接作主语 作宾语 跟在特定动词后 (如 want, hope) 跟在特定动词后 (如 enjoy, finish) · 例句对比： · I stopped to smoke. (我停下来去抽烟。——表示目的) · I stopped smoking. (我戒烟了。——表示动作本身) · He forgot to buy milk. (他忘了去买牛奶。——动作未发生) · He forgot buying milk. (他忘了买过牛奶。——动作已发生) 练习与巩固 一、单项选择 (选择最佳答案填空) 1. He decided ______ to the party. A. not to go B. to not go C. not going D. not go 1. It’s important ______ English well. A. learn B. learning C. to learn D. learned 1. My mother made me ______ my homework. A. do B. to do C. doing D. done 1. I heard her ______ in the next room. A. sing B. to sing C. sang D. sings 1. He went to the library ______ some books. A. borrow B. to borrow C. borrowing D. borrowed 二、用动词的适当形式填空 (动词不定式或动名词) 1. It’s easy ______ (say) than ______ (do). 1. He stopped ______ (smoke) a year ago. 1. I enjoy ______ (read) English novels. 1. She wants ______ (be) a doctor. 1. We often see him ______ (play) basketball on the playground. 三、根据句意完成句子 (补全句子) 1. It’s kind of you (帮助我) ______________. 1. He decided (去北京) ______________ next month. 1. My teacher told me (不要迟到) ______________. 1. I saw him (过马路) ______________ just now. 1. (学好英语) ______________ is not easy. 四、改写句子 (按要求改写句子) 1. He is too young to go to school. (改为复合句) ____________________________________ 1. It is difficult for us to learn English well. (改为简单句) ____________________________________ 1. I want to go home. (改为否定句) ____________________________________ 1. He makes me laugh. (改为被动语态) ____________________________________ 1. To see is to believe. (用动名词作主语改写) ____________________________________ 参考答案 一、单项选择 1. A 2. C 3. A 4. A 5. B 二、用动词的适当形式填空 1. to say; to do 2. smoking 3. reading 4. to be 5. play 三、根据句意完成句子 1. to help me 2. to go to Beijing 3. not to be late 4. cross the road 5. To learn English well 四、改写句子 1. He is so young that he can’t go to school. 1. Learning English well is difficult for us. 1. I don’t want to go home. 1. I am made to laugh by him. 1. Seeing is believing. 学科网（北京）股份有限公司 $