Unit 2 Inspiring people语法精讲精练（It作形式主语不定式句型和 that 从句句型） 2026-2027学年人教版（新教材）九年级上册英语

**基本信息** 聚焦It作形式主语的不定式与that从句句型，通过基础辨析-综合转换的分层设计，强化语言结构理解与灵活运用，培养语言能力与思维品质。 **分层设计** |层次|知识覆盖|设计特色| |----|----------|----------| |基础层|核心句型结构（It's+adj.+for/of sb. to do）|20道单项选择，考查不定式否定、句式变形等基础考点| |辨析层|for/of精准区别|通过易混形容词（如good）对比题，训练修饰对象判定思维| |综合转换层|不定式与that从句互换、虚拟语气|20道句型转换题，实现单一知识点到跨句型应用的进阶|

答案解析 第一部分 It作形式主语不定式句型 考点精练 一、单项选择（20小题） 1. 答案：C。解析：固定句型It is + adj. + for sb. to do sth.，it是形式主语，真正主语是后面不定式to do，因此填to take；A动词三单、B动名词、D将来时均不符合句型结构。 2. 答案：A。解析：rude粗鲁的，形容人的品行，用of sb. to do结构，完整结构It’s rude of you to laugh at others（你嘲笑别人很无礼），缺少to do不完整，排除B/C/D。 3. 答案：C。解析：第一空固定搭配be kind to sb.对某人友善；第二空kind形容人善良，用It’s kind of sb. to do，因此依次填to; of。 4. 答案：A。解析：It作形式主语固定用法，句型It is + adj. to do sth.，this/that/they不能充当形式主语。 5. 答案：A。解析：meaningful有意义的，修饰“支持慈善”这件事，用for sb.，后接不定式to support，结构It’s meaningful for us to support charities。 6. 答案：B。解析：it是形式主语，本句真正主语是后置的不定式短语for Lisa to move。 7. 答案：C。解析：it作形式主语；exercise锻炼这件事对人有益，good修饰事情用for，句型It is good for you to do sth.。 8. 答案：D。解析：generous慷慨的，形容人的品格用of；donate money捐款，raise是筹款，句意“捐钱给贫困地区”用to donate。 9. 答案：C。解析：固定形式主语It is + adj. of sb. to do，honest形容人诚实，用of，不定式to return作真正主语。 10. 答案：A。解析：brave勇敢的，用来评价医生的高尚品格，使用It’s brave of sb. to do结构。 11. 答案：C。解析：it作形式主语；careless粗心的，形容科学家的行事品质，搭配of。 12. 答案：A。解析：it作形式主语；clever聪明的，夸赞学生的特质，用of sb. to do。 13. 答案：C。解析：It作形式主语固定句型It is not polite to do sth.，this/that/he无法充当形式主语。 14. 答案：A。解析：I think后接宾语从句，从句用it’s作形式主语；necessary形容事情，搭配for；for后用人称宾格Jim and me。 15. 答案：B。解析：不定式否定结构not to do，句意“学生上课不迟到很重要”，A结构错误，C/D逻辑不符。 16. 答案：B。解析：句型it’s useful for sb. to do sth.，不定式to learn作真正主语。 17. 答案：C。解析：dangerous危险，形容“孩子在街上玩耍”这件事，用for sb.；固定结构It’s + adj. + for sb. to do。 18. 答案：B。解析：一般疑问句形式Is it possible for sb. to do sth.，it为形式主语，to learn是真正主语。 19. 答案：C。解析：difficult困难，形容野生生存这件事，搭配for；it充当形式主语。 20. 答案：C。解析：easy修饰“赶上同学”这件事，用for sb.；固定结构It’s + adj. + for sb. to do。 二、句型转换（10小题，每空一词） 1. 答案：to read。解析：原句动名词Reading作主语，同义转换用it作形式主语，真正主语改为不定式to read，It is bad for your eyes to read in the sun。 2. 答案：To work; is。解析：It’s adj. for sb. to do = To do sth. is adj. for sb.，不定式放句首作主语，谓语动词用单数is。 3. 答案：is easy。解析：原句It’s easy for people to build…，同义改写主语this house，sth. is easy for sb. to do某物便于某人做。 4. 答案：It’s; to keep。解析：动名词主语互换it形式主语结构，It’s good for us to keep a pet。 5. 答案：What is; to do。解析：划线部分to send me a gift是真正主语（动作），提问动作使用疑问词what，保留原句型It’s adj. of sb. to do。 6. 答案：It’s; to。解析：动名词Shaking hands作主语，转换为it作形式主语，It’s very common for us to shake hands。 7. 答案：It; kind of; to。解析：Sb. be kind to do = It is kind of sb. to do，固定人品形容词句型互换。 8. 答案：It’s easy for; to。解析：原句Birds catch them easily，转换为it形式主语It’s easy for birds to catch them for food。 9. 答案：It’s necessary。解析：To do sth. is necessary for sb. = It’s necessary for sb. to do sth.，it作形式主语替换句首不定式。 10. 答案：It’s hard/difficult。解析：原句“没有训练我们到不了山顶”= 没有训练我们很难登顶，It’s hard/difficult for us to reach the top without proper training。 第二部分 It's + adj. + that从句 考点精练 句型转换（10小题） 1. 答案：It’s; that。解析：It is + adj. for sb. to do 与 It is + adj. that sb. (should) do 同义转换，it作形式主语，that引导主语从句。 2. 答案：It’s believed。解析：固定句型It’s believed that…人们相信……，替换原句People believe that。 3. 答案：It’s probable。解析：原句We will probably finish…，转换为形式主语从句It’s probable that…（很可能……）。 4. 答案：It’s possible for; to。解析：It is likely that sb. will do = It is possible for sb. to do，that从句与for不定式互换。 5. 答案：It seemed。解析：Sb. seemed to do = It seemed that + 完整句子，it作形式主语，主句时态保持一般过去时seemed。 6. 答案：for us to。解析：It’s necessary that we (should) help = It’s necessary for us to help，that主语从句替换为for不定式结构。 7. 答案：for him to。解析：It’s impossible that he will finish = It’s impossible for him to finish，that从句与for不定式同义转换。 8. 答案：It; of。解析：原句so selfish that…改写为it形式主语评价人品句型It was selfish of sb. to do。 9. 答案：too hard for; to understand。解析：原句句子太难我看不懂，转换固定结构It’s too + adj. for sb. to do sth.（对某人来说太……而不能……）。 10. 答案：is; for。解析：固定句型It is known for sb. that…（某人都知道……），替换原句We know that。 学科网（北京）股份有限公司 $ 人教版（新教材）九年级上册Unit 2 Inspiring people语法讲练 It 作形式主语不定式句型和 that 从句句型 核心语法1：It作形式主语（不定式句型） 知识点1 基础定义与核心句型 当句子真正主语为不定式(to do)/that从句时，直接置于句首会导致句子头重脚轻。因此用无实义的 it 作形式主语 放置句首占位，将真正主语后置，平衡句子结构。 核心两大不定式句型：It's + adj. + for sb. to do sth. / It's + adj. + of sb. to do sth. 知识点2 It's + adj. + for sb. + to do sth.（形容事情属性） 1. 含义：做某事对某人来说是……的。形容词仅描述事情本身的客观性质（难易、重要、有用、危险等），不评价人的品格。 2. 核心结构：It + be + 事物类形容词 + for + 人称宾格 + to do sth. 3. 常用事物类形容词：important, necessary, easy, difficult, possible, impossible, dangerous, useful, meaningful, boring, interesting 4. 完整句式变形（含高频不定式否定考点） 句式类型 结构公式 例句+解析 肯定句 It + be + adj. + for sb. + to do It is important for us to learn English. 解析：important形容“学英语”这件事，it为形式主语，真正主语为to learn English be动词否定句 It + be + not + adj. + for sb. + to do It isn't necessary for you to get up early. 解析：否定词修饰整体句式，表“没必要做某事” 不定式否定句（高频考点） It + be + adj. + for sb. + not to do It's dangerous for kids not to watch traffic lights.解析：否定词not置于to前，否定不定式动作本身 一般疑问句 Be + it + adj. + for sb. + to do? Is it hard for him to finish the task? 解析：be动词提前，其余结构不变 特殊疑问句 疑问词 + be + it + adj. + for sb. + to do? Why is it difficult for her to solve the problem? 解析：疑问词前置，采用陈述语序 5. 必考规则：不可转换为 Sb. be adj. to do 句型 ❌ I am difficult to study math.（错误，difficult仅形容事情，不形容人） ✅ It is difficult for me to study math.（正确） 6. 同义句转换：It’s + adj. + for sb. to do = To do sth. + be + adj. for sb. 例：It’s hard for me to climb mountains. = To climb mountains is hard for me. 知识点3 It's + adj. + of sb. + to do sth.（形容人品质） 1. 含义：某人做某事，（这人）真……。形容词专门评价人的性格、品德、处事态度。 2. 核心结构：It + be + 人品类形容词 + of + 人称宾格 + to do sth. 3. 常用人品类形容词：kind, polite, clever, careless, brave, honest, rude, generous, thoughtful, stupid 4. 完整句式变形 句式类型 结构公式 例句+解析 肯定句 It + be + adj. + of sb. + to do It is kind of you to help me. 解析：kind赞美人的善良品质，用of be动词否定句 It + be + not + adj. + of sb. + to do It wasn't polite of him to interrupt others. 解析：否定人的行为品质 不定式否定句 It + be + adj. + of sb. + not to do It's careless of her not to lock the door. 解析：否定动作，体现人的粗心特质 一般疑问句 Be + it + adj. + of sb. + to do? Is it brave of him to save the child? 解析：be动词提前，句式结构不变 5. 核心必考转换规则 仅人品评价类形容词可同义转换：It's adj of sb. to do = Sb. be adj. to do 例：It's kind of you to help me. = You are kind to help me. 例：It was careless of him to lose keys. = He was careless to lose keys. 知识点4 for sb. vs of sb. 精准辨析（考试核心） 摒弃错误“组词通顺法”，采用修饰对象判定法（唯一精准考试标准）： 1. 形容词修饰事情、客观属性 → 用 for sb. 2. 形容词修饰人、品格性格 → 用 of sb. 对比维度 for sb. of sb. 修饰对象 事件的难易、重要性、益处 人的品德、性格、行为态度 代表词汇 important, difficult, dangerous, good（有益的） kind, polite, careless, brave, good（善良的） 句型转换 不可转换 Sb. be adj. to do 可转换 Sb. be adj. to do 人称格式 必须用宾格 必须用宾格 中考最高频易混：good 双向搭配 - It's good for you to exercise.（good形容运动有益，修饰事） - It's good of you to help me.（good形容人心善，修饰人） 考点精练 一、单项选择（共20小题） 从A、B、C、D四个选项中，选出可以填入空白处的最佳选项。 ( )1．It is interesting for students ________ part in the school’s Arts and Sports Festival. A．takes B．taking C．to take D．will take ( )2．It’s rude ________ laugh at others when they make mistakes. A．of you to B．for you to C．of you D．for you ( )3．Our teacher is kind ________ us and it’s very kind ________ her to help us with our English. A．to; to B．of; of C．to; of D．of; to ( )4．________ is boring to go to the zoo on Sunday. A．It B．This C．That D．They ( )5．It’s meaningful ________ us ________ charities. A．for; to support B．of; to support C．for; support D．of; supporting ( )6．“It was almost impossible for Lisa to move.” The real subject of this sentence is ________. A．impossible B．for Lisa to move C．almost D．Lisa ( )7．_______ is good _______ you to take exercise every day. A．It; with B．This; to C．It; for D．That; of ( )8．It is generous ____him _____so much money to the people in poor areas. A．of, to raise B．for, to raise C．for, to donate D．of, to donate ( )9．________ is very honest of you ________ the money you found on the playground. A．That; to return B．This; returning C．It; to return D．It; returning ( )10．It is brave ________ thousands of doctors to save people from COVID-19. Sometimes they risk losing their lives. A．of B．to C．for D．from ( )11．—What do you think of genetically modified food (转基因食品)? —We all think ______ is careless ______ some scientists to say it is safe before doing any experiment. A．that, for B．it, for C．it, of D．that, of ( )12．— Did you watch the TV show Super Brain（最强大脑）on Jiangsu TV yesterday? — Yes. ______ was really clever _______ a student to remember so many faces. A．It; of B．That; of C．It; for D．That; for ( )13．________ is not polite to talk with your mouth full. A．That B．He C．It D．This ( )14．I think ________ necessary ________ to take more exercise. A．it’s; for Jim and me B．it’s; to Jim and me C．that; for Jim and I D．that’s; to Jim and I ( )15．It is important for students ________ for class. A．not be late B．not to be late C．to be late D．be late ( )16．I think it’s useful for you ________ a second language. A．learn B．to learn C．learning D．to learning ( )17．________ very dangerous ________ children ________ in the street. A．It’s; for; play B．It’s; of; play C．It’s; for; to play D．That’s; for; to play ( )18．Is ________ possible for us ________ a foreign language well in a short time? A．one; learn B．it; to learn C．that; to learn D．this; learning ( )19．Usually, ________ is difficult ________ baby pandas to live in the wild. They are not good at finding food for themselves. A．that; for B．this; of C．it; for D．it; of ( )20．It’s not easy ________ Peter ________ catch up with the other students. A．for; in B．to; on C．for; to D．for; for 二、句型转换（共10小题） 按要求完成下列句子，每空一词。 1．Reading in the sun is bad for your eyes.（改为同义句） It is bad for your eyes ________ ________ in the sun. 2．It’s easy for the boy to work out this maths problem. (改为同义句) ________ ________ out this maths problem ________ easy for the boy. 3．It’s easy for people to build and move this house. (改为同义句) This house ________ ________ for people to build and move. 4．Keeping a pet is good for us. (改为同义句) ________ good for us ________ ________ a pet. 5．It is kind of her to send me a gift.（对划线部分提问） ________ ________ kind of her ________ ________? 6．Shaking hands is very common for us.（改为同义句） ___________ very common for us ___________ shake hands. 7．My sister is kind to take care of others. (改为同义句) __________ is very __________ __________ my sister __________ take care of others. 8．Birds catch them for food easily. (改为同义句) ______ ______ ______ birds ______   catch them for food. 9．To plant trees every year is necessary for us. (改写句子，句意不变) ________ ________ for us to plant trees every year. 10．We can’t reach the top without proper training. (改为同义句) ________ ________ for us to reach the top without proper training. 核心语法2：It's + adj. + that从句（形式主语从句句型） 知识点1 核心语法讲解 1. 定义：it为形式主语，that引导的完整陈述句是真正主语，用于对整件事情发表评价、判断、感慨。 2. 基础公式：It + be + 形容词 + that + 完整主谓陈述句（陈述语序） 3. 基础语气（客观陈述）常用形容词：clear, true, certain, obvious, surprising, natural 例：It's clear that he works hard. 很明显他学习很努力。 知识点2 重难点：that从句虚拟语气（必考） 1. 触发条件：形容词表「重要、必要、理应、诧异」 触发词汇：important, necessary, strange, natural, essential 2. 核心规则：从句谓语固定用 (should) + 动词原形，should 可省略 3. 完整拓展规则 ① 时态不变：主句为过去式 It was + adj.，从句仍用 (should) do，无需倒退时态 例：It was necessary that he (should) finish the work on time. ② 否定结构：(should) not + 动词原形 例：It's strange that he (should) not reply to my message. ③ 特殊翻译：strange类句型可译“竟然” 例：It's strange that she should refuse the prize. 她竟然拒绝了奖项。 知识点3 句型同义替换 that主语从句可与for不定式句型互换，语义完全一致 It is important that we (should) learn English. = It is important for us to learn English. 考点精练 句型转换（共10小题） 按要求完成下列句子，每空一词。 1．It is necessary for translators to polish works repeatedly. (改为同义句) ________ necessary ________ translators should polish works repeatedly. 2．People believe that hard work leads to great success. (改为同义句) ________ ________ that hard work leads to great success. 3．We will probably finish the work by Friday. (改为同义句) ________ ________ ________ that we will finish the work by Friday. 4．It is likely that she will pass the math exam. (改为同义句) ________ ________ ________ ________ her ________ pass the math exam. 5．Jack seemed to know every single detail of the case. (改为同义句) ________ ________ that Jack knew every single detail of the case. 6．It’s necessary that we help the poor. (改为同义句) It’s necessary ________ ________ ________ help the poor. 7．It’s impossible that he will finish the hard work in such a short time.(改为同义句) It’s impossible __________ ___________ __________ finish the hard work in such a short time. 8．Eddie was so selfish that he ate up all the food.（改为同义句） _________ was selfish ________ Eddie to eat up all the food. 9．The sentence is so hard that I can’t understand it. （改为同义句） It’s ________ ________ ________ me ________ ________ the sentence. 10．We know that Christmas is a Western festival. (改为同义句) It _______ known _______ us that Christmas is a Western festival. 学科网（北京）股份有限公司 $