【语法讲解】高中英语--名词性从句专题讲解(详细)

名词性从句 概念 在复合句中起名词作用的从句叫作名词性从句。 种类 主语从句、宾语从句、表语从句和同位语从句。 注：由于名词性从句在句中不同的句法功能（即名词性从句在复合句中，能充当主语、宾语、表语、同位语等。），相应地，名词性从句可以分为主语从句、宾语从句、表语从句和同位语从句。 引导词 类别 从属连词 连接代词 连接副词 主语从句 主语从句可直接放在句首，也可用形式主语it代替，而将主语从句后置。 ? that引导的主语从句 1) that引导的主语从句置于句首（that此时在从句中不充当任何成分，无含义，只起连接作用，不能省略） That the earth moves around the sun is known to all. 注：从句作主语，谓语动词用单数形式。 2) 在that引导的主语从句中，常用it作形式主语，that引导的真正的主语从句后置，常见的此类句型有： ① It+系动词+形容词+that从句。 常用于这种结构的形容词有： necessary 必要的 certain 明确的 功能 指起连接作用，不充当从句中的任何成分 既起连接作用，本身又作从句的主语、宾语、表语或定语 既起连接作用，本身又作从句的状语 that, whether, if who, whom, whose, which, what, whoever, whatever, whichever when, where, how, why，whenever，wherever，however 例词 right (un)likely strange natural 正确的 clear 清晰的 可能的 明显的 重要的 （不）可能的 possible 奇怪的 obvious 自然的 important It is likely that he can’t come to the meeting. It is obvious that you have made a big mistake. 注：It is necessary/important/surprising/strange/unthinkable/unbelievable/incredible that+主语(should)+动词原形+其它。 e.g. It is necessary that a college student (should) master one or two foreign languages. It is strange that you (should) trust Jane. ② It+系动词+名词+that从句。 常用于这种结构的名词有： a pity a shame 遗憾 令人遗憾的事 a honor a wonder no wonder no surprise 荣耀 奇迹 难怪 不奇怪 good news 好消息 事实 a fact It is a pity that you didn’t attend the lecture yesterday. It is no wonder that you’ve achieved so much success. ③ It+ be+过去分词+that从句。 常用于这种结构的过去分词有： said heard decided advised 据说 有人听说 作出决定 有人建议 told reported suggested ordered thought 有人告诉 据报道 有人建议 根据命令 有人认为 remembered 有人记得 认为 considered hoped 有人希望 well-known 很著名 announced 据宣布 It is reported that no passengers were injured in the accident. It is generally considered that boys are better at science than girls. 注：It is suggested/advised/ordered/requested/insisted/demanded +that+主语(should)+动词原形+其它。 e.g. It is suggested that you(should) spend more time in studying English. ④ It+动词（+宾语或状语）+that从句。 常用于这种结构的动词有： seem matter 显得 重要 happen occur 碰巧 出现 turn out 结果是 It happened to me that I was away when he called. It occurred to me that we should get in touch with the manager. ? whether/if引导的主语从句 whether引导的主语从句即可以放在句首，也可以放在句末，但if引导的主语从句只能放在句末，前面需用it作形式主语。whether， if只起连句中不作成分，且不可省略。 Whether you can succeed or not depends on how hard you work at it. （whether引导的主语从句放在句首） It is unknown whether/if he has agreed to my plan. （主语从句是whether/if he has agreed to my plan, it作形式主语） ? 连接代词或连接副词引导的主语从句 1） 连接代词what, who, whom, , whose, which , whatever, whoever, whichever等在从句中作主语、宾语、表语、定语,不可以省略。 What he said just now is true. Who breaks the law will be punished. 注：①whoever和whatever引导的名词性从句一般不用it作形式主语。 ②what 引导的主语从句一般按单数对待，但在实际使用中，其单复数取决于其成分的含义。 e.g. What the kid wanted was only a new school bag. （schoolbag是可数名词单数，谓语动词用单数） What they need are a car and some water. （a car and some water表示复数概念，谓语动词用复数） 2） 连接副词when, where, why, how，whenever，however，wherever等在从句中作状语。 Why they suddenly disappeared remains a mystery. （why在从句中作原因状语） When we’ll go for a picnic isn’t known. （when在从句中作时间状语） 宾语从句 ? 句法功能 1) 作动词的宾语 ①大多数位于及物动词后。 I hope (that) you can join us in the game. I doubt whether/if he will come to the wedding. ②有些动词短语后。