名词性从句-2025-2026学年高中英语选修三语法知识点全解（外研版）

高中选修3外研版 【语法专版】B版考点精析 语法专版 【专题】名词性从句 高中语法专项突破 考频分析 高二外研版选修3中，名词性从句是重点语法模块，考频占句法总量的15%左右，涉及试卷多个 核心题型：单项选择2-3题、完形填空1-2题、语法填空2-3题、阅读理解（辅助理解长难句）、书 面表达（提升句式复杂度与表达准确性）。在综合应用类题目中，名词性从句的连接词选用、语序 及与其他从句的区分往往是解题关键。 考查内容 。从句类型辨析：主语从句、宾语从句、表语从句、同位语从句的句法功能与引导词选择 ·引导词使用：连接词that if whether、连接代词what who whom whose which、连接副词when where why how的区别与适用场景 ·语序与时态：陈述句语序的坚持，主从句时态呼应（如主句过去时从句用相应过去时态）及特殊情 况（如客观真理用一般现在时） 知识点一：名词性从句的分类及基础用法 1.主语从句（在句中作主语，常用t作形式主语） 1.连接词： ·ht(无意义，不充当成分) 。whether(是否) 。what/who/which(什么/谁/哪个，充当主语/宾语/表语) 2.例句： ●That he will come is certain.(that引导主语从句，置于句首) 。It is important whether we can finish the work on time.(it作形式主语，whether引导的从句作真正 主语) 1 高中选修3外研版 【语法专版】B版考点精析 2.宾语从句（在句中作及物动词或介词的宾语） 1.连接词： 。hat(可省略) ·if/whether(是否) ·what/how/why(什么/如何/为什么，充当相应成分) 2.例句： ●I think(that)she is right..(that引导宾语从句，可省略) ·He asked if they would go there by bus.(if引导宾语从句，表”是否') 3.表语从句（在句中作系动词的表语） 1.连接词： ●that(不可省略) ●whether(是否) ●as if/as though(好像) 。what/where(什么/哪里，充当成分) 2.例句： ●The fact is that he has never been abroad.(that引导表语从句，说明主语的内容) ·It looks as if it is going to rain.(asif引导表语从句，表”好像”) 4.同位语从句（在句中作名词的同位语，解释说明名词的具体内容） 1.常见先行词： 。fact(事实) 。news(消息) 。idea(想法) ·promise(承诺) 2.连接词： ●ht(不可省略，不充当成分) ·whether(是否) 3.例句： ●We heard the news that our team had won.(that引导同位语从句，解释news的内容) ·There is some doubt whether he will keep his promise.(whether引导同位语从句，修饰doubt) 高中选修3外研版 【语法专版】B版考点精析 知识点二：名词性从句的分类与用法 1.主语从句（在句中作主语，引导词连接主句和从句） 1.常用引导词： ·ht(无意义，不充当成分，主句谓语常用单数) ●whether(是否) 。what(什么，指事物) 。who(谁，指人) ·when(何时) ●where(何地) 。why(为何) 。how(如何) 2.基本结构：引导词+陈述句语序（主语+谓语+其他）+主句谓语+其他 3.例句： ·That she passed the exam surprises everyone..(that引导主语从句，无意义，不充当成分；主句谓 语用单数surprises) 。What he said is very important..(what引导主语从句，在从句中作said的宾语：主句谓语用单数 is) ·Whether we will go hiking depends on the weather.(whether引导主语从句，表”是否'：主句谓语 用单数depends) 2.宾语从句（在句中作及物动词、介词或某些形容词的宾语) 1.常用引导词： 。that(可省略，无意义) 。if/whether（是否，if不用于介词后或与or not直接连用) what,who,whom,whose,which,when,where,why,how 2.基本结构：主句+引导词+陈述句语序（主语+谓语+其他） 3.例句 ●I think(that)she will come tomorrow.(that引导宾语从句，作think的宾语，可省略；从句用陈述 句语序) ●He asked if/whether we had finished the work.(if/whether引导宾语从句，作asked的宾语，表'是 否”) 。She is interested in what he is doing..(what引导宾语从句，作介词in的宾语；从句用陈述句语序) 3 高中选修3外研版 【语法专版】B版考点精析 3.表语从句（在句中作系动词的表语，位于be、look、seem等系动词后) 1.常用引导词： 。hat(无意义，不省略) ·whether(是否) what,who,when,where,why,how ·asif/as though(好像) 2.基本结构：主句主语+系动词+引导词+陈述句语序（主语+谓语+其他） 3.例句： ·The fact is that he lied to us.(that引导表语从句，作is的表语，不省略：从句用陈述句语序) ●This is where we met for the first time.(where引导表语从句，作is的表语，表地点；从句用陈述 句语序) 。It seems as if it is going to rain.(asif叼引导表语从句，作seems的表语，表”好像”) 4.同位语从句（在句中作名词的同位语，解释说明名词的具体内容) 1.常见名词：fact,newS,idea,hope,belief,suggestion等 2.常用引导词： 。ht（无意义，不充当成分，不省略) ●whether(是否) ●how等（连接代词/副词在从句中作成分） 3.基本结构：名词+引导词+陈述句语序（主语+谓语+其他） 4.例句： ·The news that our team won the game made us excited.(that引导同位语从句，解释news的内容， 不省略：从句用陈述句语序) 。I have no idea whether he will agree with us.(whether引导同位语从句，解释idea的内容，表”是 否) ●There is a suggestion that we should hold a meeting.(that引导同位语从句，解释suggestion的内容， 从句用”should+动词原形”虚拟语气，should可省略) 知识点三：名词性从句 1.主语从句 1.基础连接词（必背)： 4 高中选修3外研版 【语法专版】B版考点精析 。that(无意义，不充当成分)→例句：That he passed the exam makes his parents happy. ●whether/if(是否)→例句：Whether we will go picnic depends on the weather.. ·what(什么，充当主语/宾语/表语)→例句：What she said is true. 。who(谁，指人)→例句：Who will win the game is still unknown. 。how（如何，方式)→例句：How we solve the problem is important. 2.常用结构（易错)： 。It+be+adj.+that从句（做某事是…的）→例句：It is clear that he is lying 。It+be+n.+that从句(…的是…)一→例句：It is a fact that the earth goes around the sun. 2.宾语从句 1.基础连接词（必背）： ●that(无意义，可省略)→例句：She said(that)she would come tomorrow. 。if/whether(是否)→例句：Idon't know if he will agree with us.. 。what(什么)→例句：He asked me what I wanted to eat. 。when(何时)→例句：Could you tell me when the party will start'? 。how(怎样)→例句：Please show me how to use the machine.. 2.时态规则（核心）： 。主句为现在时/将来时，从句用任意时态→例句：I think he is reading now. 。主句为过去时，从句用过去相关时态→例句：She said she had finished her homework 3.表语从句 1.基础连接词（必背)： 。that(无意义，不可省略)→例句：The fact is that he failed the exam ●what(…的东西/事情)→例句：My idea is what we should start early. 。why(原因)→例句：The reason was why he was late for class. ·because(因为)→例句：That's because he didr't study hard. 2.常见句型（拓展)： 。The problem is whether..(间题是是否…)→例句：The problem is whether we can get there on time. 。That'swhy.(那就是…的原因)→例句：He got up late.That's why he missed the bus.. 4.同位语从句 5 高中选修3外研版 【语法专版】 B版考点精析 1.基础连接词（必背）： ·that(解释说明名词内容)→例句：The news that our team won the game made us excited, 。fact/tuth+that（事实是…)→例句：No one can deny the fact that water is important 。idea/suggestion+that(想法/建议是…)一→例句：He put forward the suggestion that we should have a rest. 2.特点（辨析)： ·与定语从句区别：同位语从句解释名词内容，定语从句修饰名词→例句：The news that he told me is true..（定语从句，that指代news);The news that he won is true.(同位语从句，解释news内 容) 考法精析 考法一：连接词that与what的辨析 核心：根据从句是否缺成分及语义需求，区分hat(不充当成分)与what（充当主/宾/表语)的用法 真题1（语法填空)： -he said at the meeting surprised all of us. 答案：What 解析：从句中said后缺宾语，需用what充当成分，意为”他所说的话”；若用that则不充当成分，从 句语义不完整。 真题2（单项选择)： The fact_he won the competition made his family proud. A.that B.what C.which D.how 答案：A 解析：从句he won the competition”结构完整，不缺成分，且先行词为fact,需用hat引导同位语从 句，解释fact的内容。what需充当成分，此处不符合语境。 考法二：连接词选择与语序综合考查 核心：结合名词性从句类型判断连接词是否充当成分及是否省略，同时确保从句使用陈述语序 真题1（语法填空）： No one knows_the famous singer will arrive.The fans have been waiting at the airport for hours. 答案：when 解析：从句'the famous singer will arrive”中缺少时间状语，需用连接副词when引导宾语从句；从 句使用”主语+谓语”的陈述语序，符合语法规则。 真题2（单项选择）： The problem is-we can solve it in such a short time. A.how B.that C.what D.if 答案：A 6 高中选修3外研版 【语法专版】 B版考点精析 解析：表语从句中”we can solve it'”主谓宾完整，缺少方式状语，应用连接副词how;if不可引导表 语从句，hat不充当成分不符合语境，what需充当成分此处不适用。 考法三：名词性从句的综合运用（分类、连接词选择与时态语序) 核心：结合名词性从句的类型判断（主语/宾语/表语/同位语从句），正确选择连接词，并遵循时态 一致与陈述语序规则 真题1（单项选择）： -he will come to the party depends on his parents'permission. A.That B.Whether C.What D.Where 答案：B 解析：从句he will come to the party'在主句中作主语，且表示”是否”，需用whether引导主语从句： that无意义不符合语境，what/where在从句中需充当成分，此处从句成分完整，故选B。 真题2（语法填空)： She told me that she_(visit)her grandparents the next day. 答案：would visit 解析：主句谓语”told?为一般过去时，从句需用相应过去时态：由时间标志词'the next day'可知，从 句表过去将来的动作，用过去将来时”would+动词原形”。 解题小妙招 连接词辨析妙招 连接词选that或what,先看从句缺成分： that不充当成分，what作主宾表语： 名词性从句表是否，whether/if要注意： 主语从句在句首，whether独当一面： 介词之后表是否，whether适用最合理。 语序判断妙招 名词性从句要记牢，陈述语序是法宝： 疑问词后接主谓，不可倒装别混淆： 连接代词副词后，主语在前谓在后： 复杂句式莫慌张，先找主谓宾结构。 综合运用妙招 名词性从句综合看，连接词、时态和语序： 连接词选that/what,成分分析是关键： whether表是否，句首介词后用它； 时态要与主句呼应，过去完成看先后： 高中选修3外研版 【语法专版】B版考点精析 被动语态be done,时态变化be来变： 陈述语序不颠倒，主谓顺序要牢记。 真题演练 演练一：单项选择试题（共10题） 1.the meeting will be held next week is still unknown to all of us. A.If B.Whether C.That D.What 2.The manager didn't tell us the project would be completed,but he promised_it would be finished on time A.when:that B.that:when C.what:if D.how:what 3.It is necessary-we should take measures to protect the environment. A.if B.whether C.that D.what 4.She asked meI had seen her keys,but I had no idea_she had left them. A.that;where B.if;that C.whether;where D.what;how 5.The facthe failed the exam again made his parents very disappointed. A.which B.what C.that D.why 6.-surprised us most washe could speak five foreign languages fluently. A.What;that B.That;what C.Which;how D.How;which 7.There is some doubtthe new policy will be carried out effectively. A.if B.whether C.that D.what 8.The teacher suggested that we_more attention to grammar rules while writing. A.pay B.paid C.will pay D.have paid 9.I wonder-the meeting-tomorrow morning A.if;will hold B.whether;will be held C.that;is held D.what;holds 10.-he told me yesterday was-he had applied for a job in a foreign company. A.That;what B.What;that C.Which;that D.What;which 演练二：填空试题（共10题） 1.The news-our school will hold a sports meeting next month excited all the students. 2.We haven't decided_we should go for a picnic this weekend. 3.-you need most now is a good rest after such a long journey. 4.It is important_we should learn to communicate with others politely. 5.The little girl asked her mother-the moon goes around the earth. 8 高中选修3外研版 【语法专版】 B版考点精析 6.I have no idea the concert will start.Could you check the ticket for me? 7.The facthe has never been abroad before doesn't stop him from dreaming of traveling around the world. 8.She was worried about_she could pass the final exam. 9.-the team will win the championship depends on their performance in the final match. 10.The doctor advisedI should avoid eating spicy food for a few days. 演练三：语法填空试题（共10空） Last week,our class had a discussion about 1.-we should learn a second foreign language.Some students thought 2.learning a second foreign language could help them in the future,while others doubted 3.-it was necessary.Our teacher toldus 4.-the key was to choose a language that interestedus most.She also mentioned the fact 5.many companies now prefer employees with foreign language skills. During the discussion,Tom shared his experience.He said 6.-he started learning Japanese two years ago because he was fond of Japanese culture.However,he worried 7.-he could keep up with the lessons. The teacher encouraged him by saying,"8.-matters is not how fast you learn,but how persistent you are." At the end of the discussion,we all agreed 9.-we should at least try to learn basic phrases of another language.There was no doubt 10.-this experience would benefit us in the long run. 答案区 演练-：1B2.A3.C4.C5.C6.A7B8.A9B10B 1.that 2.whether/if 3.What 4.that 5.if/whether 6.when 7.that 8.whether 9.Whether 10.that 演练三：1.whether2.that3.if/whether4.that5.that6.that7.whether/if8.What9.that10.that 9