U2 动词不定式作不同成分-2025-2026学年高中英语必修三语法知识点全解（沪教版）

高中沪教牛津版 必修3U2语法专项突破 语法精讲 动词不定式作不同成分 沪教牛津版·必修3Unit2 考频分析 沪教牛津版必修3-U2中，动词不定式作不同成分是重点语法模块，考频占句法总量的15%左右， 贯穿试卷核心题型：单项选择(1-2题)、完形填空(2-3题)、语法填空(23题)、书面表达（核心 考察，直接影响句子结构多样性与表达准确性)。在语境理解类题目中，动词不定式作宾语、状语 及宾补的用法往往是解题关键。 考查内容 。作主语：It作形式主语的固定句型(Itis+adj.+to do sth.)及逻辑主语表达(for/of sb.to do sth.) 。作宾语：接不定式作宾语的动词(want,decide,hope等)及“疑问词+不定式”结构 ·作表语：用于be动词后说明主语性质或内容(My goal is to learn English well) ·作定语：修饰名词时后置(the chance to go abroad)及与被修饰词的逻辑关系 。作状语：目的状语(to/in order to/so as to)、结果状语(only to do)及原因状语(be happy to do) 。作宾语补足语：接不定式作宾补的动词(ask,tell,allow等)及省to的情况(let,make,have等主动 语态) 知识点一：动词不定式作不同成分 1.作主语（表示具体动作或抽象概念，常用t作形式主语） 。直接作主语：To learn English well is important..(学好英语很重要) 。形式主语it代替：It is important to learn English well.(学好英语很重要) 2.作宾语（跟在及物动词后，表动作内容） ·常见接不定式的动词：want(想要)、decide(决定)、hope(希望)、plan(计划) ·例句：(I)She wants to buy a new dress.(她想买一条新裙子)(2)He decided to study abroad.(他 决定出国留学) 高中沪教牛津版 必修3U2语法专项突破 3.作宾语补足语（补充说明宾语的动作或状态） ·常见接不定式作宾补的动词：ask(要求)、tell(告诉)、want(想要)、teach(教) 。例句：(I)y mother asked me to clean the room.(妈妈让我打扫房间)(2)The teacher told us to be quiet..(老师叫我们安静) 4.作表语（位于系动词后，说明主语的内容或性质） 。常见系动词：be、seem、appear、become ·例句：(1)Her dream is to be a doctor.(她的梦想是成为一名医生)(2)The best way is to work hard. (最好的方法是努力工作) 5.作定语（修饰名词，表动作或用途，位于名词后） 。例句：(I)I have a lot of homework to do.(我有很多作业要做)(2)She needs a pen to write with. (她需要一支笔写字) 6.作状语（表示目的、结果、原因等） ·目的状语（常与in order to/so as to连用）：He got up early to catch the first bus.(他早起是为了赶 上第一班公交车) ●结果状语（常与only to连用表意外结果）：He hurried to the station only to find the train had left. (他匆忙赶到车站，却发现火车已经开走了) 知识点二：动词不定式作不同成分 1.作主语（表示具体动作或一件事） ·基本结构：T0+动词原形+其他成分（谓语动词常用单数形式） 例句：(I)To learn English well is important..(学好英语很重要) (2)To help others makes him happy.(帮助别人让他开心) ·常用形式主语结构（避免头重脚轻）： It+be+形容词/名词+to do sth.(it为形式主语，真正主语是todo不定式) 例句：(I)It is necessary to finish homework on time.(按时完成作业是必要的) (2)It's a good idea to travel in spring.(春天旅行是个好主意) 2.作宾语（跟在及物动词后，表动作内容） ·常见接不定式作宾语的动词：want(想要)、hope(希望)、plan(计划)、decide(决定)、try(尝 试)、leam(学习)、agree(同意) ·结构：主语+动词+to do sth 例句：(I)She wants to buy a new pen.(她想买一支新钢笔) (2)They plan to visit the museum tomorrow.(他们计划明天参观博物馆) 3.作宾语补足语（补充说明宾语的动作或状态） 高中沪教牛津版 必修3U2语法专项突破 ·常见接不定式作宾补的动词：ask(要求)、tel(告诉)、want(想要)、teach(教)、help(帮助)、 allow(允许) ·结构：主语+动词+宾语+to do sth.(help后的to可省略) 例句：(I)My mother asks me to clean the room.(妈妈让我打扫房间) (2)He often helps his sister(to)carry books.(他经常帮妹妹搬书) 4.作表语（放在be动词后，说明主语的内容或性质） ·结构：主语+be+to do sth 例句：(I)Her dream is to be a doctor.(她的梦想是成为一名医生) (2)The first step is to make a plan..(第一步是制定计划) 5.作定语（修饰名词，放在名词后，表“要做的事”） 。结构：名词+to do sth 例句：(I)I have a lot of homework to do.(我有很多作业要做) (2)He has no time to play basketball.(他没时间打篮球) 6.作状语（表示目的、原因或结果） ●表目的（常放句首或句中，可用in order to强调） 例句：(1)To catch the early bus,.she gets up at6:00.(为了赶上早班车，她6点起床) (2)He studies hard(in order)to pass the exam.(他努力学习是为了通过考试) ·表结果（常与only连用，意为“结果却…”) 例句：(I)He hurried to the station only to find the train had left..(他匆忙赶到车站，却发现火车已 经开走了) 知识点三：动词不定式作不同成分 1.作主语用法说明：表示具体的动作或行为，常位于句首，也可用t作形式主语，将不定式后置。 中考必背结构及例句： (1)To learn English well is important.(学好英语很重要。) (2)It takes me an hour to finish my homework every day.(我每天花一小时完成作业。) 2.作宾语用法说明：跟在及物动词后，作动词的宾语，表示动作的内容。 中考必背动词及例句： (I)want to do→She wants to buy a new book.(她想买一本新书。) (2)decide to do→They decide to visit the museum next week.(他们决定下周去参观博物馆。) (3)hope to do→We hope to travel to Beijing this summer..(我们希望今年夏天去北京旅行。) 口plan to do→Ie plans to learn swimming this vacation.(他计划这个假期学游泳。) 3.作宾语补足语用法说明：补充说明宾语的动作或状态，常见于“动词+宾语+不定式”结构。 中考必背动词及例句： (I)ask sb.todo→The teacher asks us to finish the task on time.(老师要求我们按时完成任务。) 3 高中沪教牛津版 必修3-U2语法专项突破 (2)tell sb.todo→My mother tells me not to play computer games too late.(妈妈告诉我不要玩电脑游 戏太晚。) (3)want sb.todo→I want my brother to help me with math.(我想让我哥哥帮我学数学。) 口advise sb.todo→The doctor advises him to eat more vegetables.(医生建议他多吃蔬菜。) 4.作表语用法说明：位于系动词后，说明主语的内容或性质。 中考常考例句： (l)Her dream is to be a teacher..(她的梦想是成为一名老师。) (2)The most important thing is to stay healthy.(最重要的事情是保持健康。) 5.作定语用法说明：修饰名词，通常位于名词之后，表示将要发生的动作。 中考常考例句： (I)I have a lot of homework to do.(我有很多作业要做。) (2)She has no pen to write with.(她没有笔写字。) 6.作状语用法说明：表示目的、结果或原因等。 中考常考结构及例句： (I)目的状语(todo)→He gets up early to catch the first bus.(他早起是为了赶上第一班公交车。) (2)结果状语(only to do)→He hurried to school,,only to find it was Sunday.(他匆忙赶到学校，却发 现是星期天。) 考法精析 考法一：动词不定式作定语的用法辨析 核心：识别不定式作定语时与被修饰名词的逻辑关系，判断不定式后是否需要加介词及介词的正确 形式 真题1（语法填空）： She is looking for a room _(live). 答案：to live in 解析：不定式作定语修饰名词“room”,逻辑上为“live in a room”,live为不及物动词，需加介词 in使语义完整。 真题2（单项选择）： We need someone_this problem. A solve B to solve C solving d solved 答案：B 解析：此处需用不定式作后置定语修饰“someone”,表示“需要某人去解决问题”，构成“someone to solve this problem”的结构，不定式符号to不可省略。 考法二：非谓语动词作主语和宾语的辨析 4 高中沪教牛津版 必修3-U2语法专项突破 核心：根据语境判断动作是具体一次性还是抽象习惯性，区分不定式和动名词作主语、宾语的用法 真题1（语法填空）： _(learn)English well requires patience and practice. 答案：Learning 解析：表示抽象概念“学好英语”这一行为本身，用动名词作主语。 真题2（单项选择）： She decided(join)the English club to improve her speaking skills. A.join B.joining C.to join D.joined 答案：C 解析：decide后接不定式作宾语，构成固定搭配decide to do sth.,表示“决定做某事”。 考法三：动词不定式的成分与被动语态结合应用 核心：判断不定式在句中所作成分，结合语境确定不定式的被动形式(to be done/to have been done) 真题1（单项选择)： He seems_in the accident yesterday.Let's go to see him A.to injure B.to be injured C.to have injured D.to have been injured 答案：D 解析：seem后接不定式作表语，“受伤”发生在“seem”之前，且主语he是动作“injure”的承受 者，需用不定式完成被动式to have been injured。. 真题2（语法填空)： The work_(finish)by next Friday,so we need to hurry up. 答案：to be finished 解析：此处用不定式作后置定语修饰名词work,表“要被完成的工作”，由时间标志词next Friday 可知动作尚未发生，用不定式一般被动式to be finished。 解题小妙招 不定式作定妙招 名词之后不定式，逻辑关系是核心： 及物动词直接跟，不及物需加介词： 名词若是人或物，行动者后to莫省。 非谓作主宾妙招 主宾非谓看习惯，抽象行为用动名： 具体一次性动作，不定式来把位占： 固定搭配要记牢，to do doing分清楚。 非谓形式时态语态妙招 5 高中沪教牛津版 必修3U2语法专项突破 非谓形式看功能，目的结果不定式： 主动进行用现分，完成主动having done: 被动完成用过分，时态先后要分明： “only+不定式”表意外，结合语境细判断。 真题演练 演练一：单项选择试题（共10题） 1.It is important_a foreign language well in modern society. A learn B learning C to learn D learned 2.She enjoysclassical music while studying A listen B listening C to listen D listened 3.the early bus,he got up at 5:00 a.m. A Catch B Catching C To catch D Caught 4.The teacher asked us_quiet during the exam. A be B being C to be D been 5.by the beautiful scenery,they decided to stay another day. A Attracting B Attracted C To attract D Attract 6.He pretendedwhen his mother came into the room. A to read B reading C to be reading D read 7.many times,he still couldn't solve the math problem A Told B Telling C Having told D To tell 8.My brother wants_a doctor in the future. A become B becoming C to become D became 9.The book on the desk is mine. A lying B lied C to lie D lie 10.They hurried to the airport,only the flight had been cancelled. A finding B to find C find D found 演练二：填空试题（共10题） 1.She needs a notebook_(write)down new words. 2.-(swim)in the river is dangerous. 3.He promised(return)the book next week. 4.The girl(wear)a red dress is my sister. 6 高中沪教牛津版 必修3U2语法专项突破 5.I have no time(watch)TV tonight. 6.(finish)the work on time,we need to work together. 7.She suggested(go)for a walk after dinner. 8.The problem(discuss)at the meeting yesterday is very important. 9.He seems(know)the truth already 10.(not receive)his reply,she decided to call him. 演练三：语法填空试题（共10空) Ihave always dreamed of_(be)a writer.Last year,I decided-(take)a creative writing course to improve my skills.(attend)the course was one of the best decisions I ever made.The teacher encouraged us_(write) every day,even if it was just a few sentences. One day,we were asked-(describe)a childhood memory.I chose-(write)about the summer I spent with my grandparents.-(grow)up in the city,I had never experienced life on a farm before.I remember -(help)my grandfather feed the chickens and(pick)vegetables in the garden.Those days were so happy that I often feel like(go)back 答案区 演练-：1.C2.B3.C4.C5.B6.C7.A8.C9.A10B 演练二：1.to write2.Swimming3.to return4.wearing5.to watch 6.To finish 7.going 8.discussed 9.to have known 10.Not having received 演练三：1.being2.to take3.Attending4.to write5.to describe 6.to write 7.Growing 8.helping 9.picking 10.going 7