be supposed to be expected to 的用法it 作形式主语-2025-2026学年九年级英语全一册语法知识点全解（人教版）

初三全一册人教版 【语法专版】 核心语法精解 语法专版 【专题】be supposed to/be expected to的用 法，t作形式主语 语法专项突破 考频分析 初三人教版中，be supposed to/be expected to的用法和it作形式主语是重点语法模块，考频占句法 总量的15%左右，贯穿试卷多个核心题型：单项选择(1-2题)、完形填空(2-3题)、语法填空(1-2 题)、书面表达（核心考察，直接影响句子结构的规范性与表达的准确性）。在语境理解类题目中， be supposed to/be expected to的语义辨析及it作形式主语的句型转换往往是解题关键。 考查内容 ·基础结构辨析：be supposed to与be expected to的语义侧重（理应/被期望）、人称搭配及否定形式： it作形式主语时”it+be+adj.n.+todo/that从句的基本句型结构： 。语境应用匹配：根据上下文语境选择be supposed to/be expected to表达不同语气，识别真实主语为 不定式或从句时t作形式主语的句式： ·句式转换与改写：主动语境下be supposed to/be expected to的同义替换，将真正主语后置的句子改 写为t作形式主语的句型。 知识点一：be supposed to/be expected to的用法及it作形式主语 1.be supposed to的用法（表示“应该；被期望”，强调责任或规定） 1.基本结构：主语+be supposed to+动词原形 2.例句： ·You are supposed to arrive on time for class.(你应该准时上课。) ·He is supposed to finish the work today..(他被期望今天完成这项工作。) 3.否定形式：be not supposed to(不应该) 例句：We are not supposed to talk loudly in the library.(我们不应该在图书馆大声说话。) 1 初三全一册人教版 【语法专版】 核心语法精解 2.be expected to的用法（表示“被期望；预计”，强调他人的期望或预测） l.基本结构：主语+be expected to+动词原形 2.例句： ·She is expected to win the competition.(她有望赢得比赛。) ·The meeting is expected to start at3p.mn.(会议预计下午3点开始。) 3.t作形式主语（代替真正主语，避免句子头重脚轻） l.常见结构：It+be supposed to/be expected to+动词原形+that从句（真正主语） 2.例句： ·It is supposed that he will come tomorrow.(人们认为他明天会来。) ·It is expected that the rain will stop soon.(预计雨很快会停。) 知识点二：be supposed to/be expected to的用法及it作形式主语 1.be supposed to的用法 1.基本含义：表示“应该：被期望”，强调根据规则、规定或他人的期望应该做某事。 2.结构：主语+be supposed to+动词原形 否定形式：主语+be not supposed to+动词原形 3.例句： ●You are supposed to arrive on time for class.(你应该准时上课。) ·He is not supposed to smoke here.(他不应该在这里抽烟。) 4.特殊用法：be supposed to have done表示“本应该做某事（但未做）” 例句：She was supposed to have finished her homework,but she didn't.(她本应该完成作业的，但她没 有。) 2.be expected to的用法 1.基本含义：表示“被期望；预计会”，侧重于他人或事物对主语的期望或预测。 2.结构：主语+be expected to+动词原形 3.例句： ·We are expected to work hard.(我们被期望努力工作。) ·The meeting is expected to start at9a.m.(会议预计上午9点开始。) 初三全一册人教版 【语法专版】 核心语法精解 3.t作形式主语 1.基本用法：当不定式(todo)、动名词(doing)或从句作主语时，为避免句子头重脚轻，常用it作 形式主语，将真正的主语放在句末。 2.结构：It+be+形容词/名词+(for sb.)+to do sth.(不定式作真正主语) 例句： ·It is important(for us)to learn English well..(学好英语对我们来说很重要。) 。It is a good idea to take a walk after dinner.(晚饭后散步是个好主意。) 3.结构：It+be+形容词+ofsb.+to do sth.(形容词描述人的品质，如kind,clever,foolish等) 例句：It is kind of you to help me.(你帮助我真是太好了。) 4.结构：It+be+名词+hat从句（从句作真正主语） 例句：It is a fact that the earth is round.(地球是圆的，这是事实。) 知识点三：be supposed to/be expected to的用法与it作形式主语 1.be supposed to的基础用法与搭配（中考必背） 1.表示“应该/理应做某事”（强调责任、义务或规定） 例句：We are supposed to finish our homework before class.(我们应该在课前完成作业。) 2.表示“被期望/被要求做某事”（含被动含义） 例句：You are supposed to wear uniforms at school..(学校要求你们穿校服。) 3.否定形式：be not supposed to do(不应该做) 例句：He is not supposed to smoke in the library. 2.be expected to的基础用法与搭配（中考常考） 1.表示“预计/预料做某事”（基于推测或安排） 例句：The train is expected to arrive at9:00a.m.(火车预计上午9点到达。) 2.表示“被期望做某事”（强调他人的期待） 例句：Children are expected to respect their parents.(孩子们应该尊敬父母。) 3.被动结构拓展：Sb.is expected to do sth 例句：She is expected to win the competition.(她被期望赢得比赛。) 3.t作形式主语的固定句型（中考核心） 1.It is supposed that..(人们认为/据推测…) 例句：It is supposed that the meeting will be held tomorrow.(人们认为会议明天举行。) 3 初三全一册人教版 【语法专版】 核心语法精解 2.It is expected that..(预计/人们期望.…) 例句：It is expected that the weather will be fine next week.(预计下周天气晴朗。) 3.Itis+adj.+to be supposed to do(做某事被认为是…的) 例句：It is important to be supposed to follow the rules.(遵守规则被认为是重要的。) 解题小妙招 be supposed to与be expected to辨析妙招 be supposed to重规定，责任义务要记牢； be expected to表预测，外界期望是核心； 时间标志看语境，时态语态要匹配： 主动结构主谓明，被动be加done莫忘记。 t作形式主语转换妙招 t作形式主语时，真正主语藏后面： 不定式或that从句，转换主语找对应： It is supposed that变，主语+be supposed to be: It is expected to转，主语+be expected to do: 时态保持要一致，结构转换不改变。 综合运用妙招 识别it形主结构，先找真正主语藏： 转换牢记两规则，不定式与从句换： be supposed/expected to选，规定预测是关键： 时态语态要准确，主动被动看主谓： 单选注意无引号，语法填空看搭配。 考法精析 考法一：be supposed to与be expected to用法辨析 核心：根据语境判断是强调”按规定/责任应该”还是”外界预测/期望”，选择正确搭配 真题1（单项选择)： at the airport two hours before the flight takes off. A.are supposed to B.are expected to C.supposed to D.expected to 答案：A 解析：句意为”我们应该在飞机起飞前两小时到达机场”，强调按规定的责任，用be supposed to;:主 语为we,be动词用are,故选A。 4 初三全一册人教版 【语法专版】 核心语法精解 真题2（语法填空)： The new movie (expect)to win several awards at the film festival next month. 答案：is expected 解析：句意为'这部新电影预计在下个月电影节上赢得多个奖项”，强调外界预测，用be expected to: 主语为单数，且描述现在的预测，be动词用is,故填is expected。 考法二：t作形式主语的句型转换 核心：将以it为形式主语的be supposed to/be expected to句型与其他结构（不定式、that从句）进行 转换，保持句意不变 真题1（句型转换)： It is expected to take two hours to finish the work.(改为同义句) The work__take two hours to finish. 答案：is expected to 解析：根据知识点三”与不定式结构的转换”规则，It is expected to+动词原形可转换为主语+is expectedto+动词原形，原句真正主语为to finish the work,转换后主语为The work,故填is expected to。 真题2（单选题)： It is supposed that the exam will be easy..(改为简单句) The exam be easy. A.is supposed to B.was expected to C.is expected to D.was supposed to 答案：A 解析：根据知识点三”与that从句的转换”规则，It is supposed that+从句可转换为主语+is supposed to+be+形容词，原句为一般现在时，且强调按规定应发生的情况，用be supposed to结构，故选A。 考法三：be supposed to/be expected to与it作形式主语的综合转换 核心：掌握It is supposed/expected to.与主语+be supposed/expected to..及that从句的转换，能根据 语境准确运用不同结构 真题1（单项选择)： It is expected that the meeting at 3 p.m.yesterday. A.starts B.started C.is started D.was started 答案：B 解析：It is expected that后接从句，从句时态与实际情况一致，由时间标志词“yesterday”可知用一 般过去时，stat为不及物动词无被动语态，故选B。 真题2（语法填空）： The work (suppose)to be finished last week,but he didn't complete it. 答案：was supposed 解析：此处表示“本应该完成”，用be supposed to have done结构，由“last weel”可知be动词用 初三全一册人教版 【语法专版】核心语法精解 过去式was,故填was supposed。 真题演练 演练一：单项选择（共10题） 1.Students keep quiet in the reading room. A.are supposed to B.are expected to C.supposed to D.expected to 2.The meeting start at 9 a.m.,but it was delayed by the rain. A.is supposed to B.was supposed to C.is expected to D.was expected to 3.is expected to rain heavily tomorrow,so take an umbrella. A.That B.It C.There D.This 4.The new bridge be completed by the end of next year. A.is supposed to B.was supposed to C.is expected to D.was expected to 5.You talk loudly in the library-it's against the rules. A.are supposed to B.aren't supposed to C.are expected to D.aren't expected to 6.Itbe a sunny day today,but it's raining now. A.is supposed to B.was supposed to C.is expected to D.was expected to 7.The exam be difficult,but most students passed easily. A.is supposed to B.was supposed to C.is expected to D.was expected to 8.It is expected the temperature will drop below zero tonight. A.that B.which C.what D.where 9.Wearrive on time for the party,but we missed the bus. A.are supposed to B.were supposed to C.are expected to D.were expected to 10.It take about two hours to drive to the mountains. A.is supposed to B.was supposed to C.is expected to D.was expected to 演练二：填空（共10题） 1.The train(suppose)to arrive at 6 p.m.,but it's late. 2.She_(expect)to win the competition because she practiced hard. 3.It(suppose)to be a holiday yesterday,but we had classes. 4.The project_(expect)to be finished by next Friday. 5.You-(not suppose)to smoke in public places 6.It_(expect)that the new park will open next month 6 初三全一册人教版 【语法专版】 核心语法精解 7.They_(suppose)to bring their textbooks to class every day 8.The game _(expect)to start at 7:30 p.m.,so don't be late. 9.It-(suppose)to rain this afternoon,so take a raincoat. 10.He(not expect)to pass the exam,but he got an A. 演练三：语法填空（共10空) It is common for people to make plans,but sometimes things don't go as they 1-(suppose)to.Last weekend,my family and I planned a picnic.We 2(expect)to go to the park at 10 a.m.However,my dad's car broke down,so we had to stay at home. It 3-(suppose)to be a sunny day,but it started raining heavily in the morning.My mom said,"We 4 (not suppose)to rely on the weather forecast completely."Later,we decided to cook lunch together.My little sister 5_(expect)to make a cake,but she burned it by accident. In the end,we watched a movie at home.Although the day didn't go as planned,we still had fun. Sometimes,unexpected things 6(expect)to happen,but they can bring new surprises! It 7(say)that "Man proposes,God disposes,"and this experience taught me that.Next time,I 8 (suppose)to prepare backup plans for outdoor activities.It 9(expect)that such small changes will make our plans more flexible.After all,the most important thing is to enjoy the time with family,no matter what 10(suppose)to happen. 答案区 演练-：1.A2B3B4.C5.B6B7.B8.A9B10.C 演练二：l.is supposed2.is expected3.was supposed4.is expected5.aren't supposed 6.is expected 7.are supposed 8.is expected 9.is supposed 10.wasn't expected 演练三：1.are supposed2.were expected3.was supposed4.aren't supposed 5.was expected 6.are expected 7.is supposed 8.am supposed 9.is expected 10.is supposed 7