英语语法--名词性从句讲解
在句子中起名词作用的句子叫名词从句(Noun Clauses）。名词从句的功能相当于名词词组, 它在复合句中能担任主语、宾语、表语、同位语、介词宾语等，因此根据它在句中不同的语法功能，名词从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。
一、引导名词性从句的连接
1. 连接代词：who，whose，whom，what，which.有词义，在从句中担任成分。
2. 连接副词：when，where，why，how有词义，在从句中担任成分，作状语。
3. 连接词：that，whether，if，as if在从句中不担任成分，有时可省略；
二. 具体分类
1、主语从句：作句子主语的从句叫主语从句。
（1）That he finished writing the composition in such a short time surprised us all.
（2）Whether we will go for an outing tomorrow remains unknown.
（3）Who will be our monitor hasn't been decided yet.
（4）Whom we must study for is a question of great importance.
（5）What caused the accident remains unknown.
(6)Where the English evening will be held has not yet been announced. 英语晚会将在哪里举行，还没有宣布。（7）Whatever you did is right.
（8）Who the watch belongs to was lost is unknown.
（9）What we need is time.
（10）What we need are good doctors.
(11) What he wants to tell us is not clear. 他要跟我们说什么，还不清楚。
(12) It is known to us how he became a writer. 我们都知道他是如何成为一名作家的。
再观察下例句子，找出主语从句。
（1）It is certain that he will win the match.
（2）It is true that he has made a very important discovery in chemistry.
（3）It is very likely that they will hold a meeting.
（4）It is strange that he should do that.
（5）It is important that we all should attend the meeting.
（6）It is strange that the man should have stuck to his silly ideas.
（7）It is a pity that we won't be able to go to the south to spend our summer vacation.
（8）It is still a mystery what caused the accident.
（9）It is said that he has gone to shanghai.(=He is said to have gone to shanghai) （10）It is known to all that the gun powder was first invented by the Chinese.
（11）It is suggested that the work should be done with great care.
（12）It happened that the two cheats were there. (=The two cheats happened to be there) 有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。常用句型如下：
（1. 2. 3 主语从句通常用should + V-原形）
（1）It + be + n. + that从句It is a pity (a shame, no wonder, etc.) that…
It is a fact that…
（2）It + be + adj. + that从句It is necessary (important, natural, strange, etc.) that …
（3）It + be + V-pp动词的过去分词+ that从句
It is suggested (requested, proposed, desired, etc.) that…
It is known to us all that…It is reported/ believed / considered /…that…
It has been proved that…已证实…
（4）It + Vi + that 从句
It happened (to sb) that…（某人）碰巧…It occurred to sb that…某人突然想起….
It matters that…重要的是…
It doesn’t matter how/whether…怎么样/是否…没有什么关系
It seems that…好像
It turned out that…
练习
1.Watch out! ___________________ smoking here shall be fined at once.(caught)
当心！无论抓到谁在此吸烟都会立刻罚款。
2.____________________________ the open ceremony gave the students much
encouragement.(attend)
校长亲自参加开幕式，这给学生带来了极大的鼓舞。
3.___________________ college students should learn more about Chinese history.(it)
我认为大学生了解更多历史很重要。
4.___________________ is clear to us.(land)
我们很清楚是谁第一个登上月球的。
5._________________________ there was a short cut to the history museum.(occur)
我突然想起去历史博物馆有条近路。
6.It is announce that ________________________ in the examination will be graded
zero.(catch)
已宣布任何被抓到在考试中作弊的学生都得零分。
7._______________________ is the salary and the chance to travel. (attract)
吸引我做这份工作的是其薪水和有去旅游的机会。
8.It matters little how a man dies; _____________________ is how he lives.(matter)
一个人是如何死的这不重要，重要的是他是怎样生活的。
9.__________________doesn’t make much difference if he wants to apply for this job.(abroad)
如果他想申请这份工作，他是否出国并没有太大的影响。
10.______________________in the game worried his coach.(make)
那个运动员在比赛中可能会犯错，这让他的教练很着急。
2.宾语从句：作句子宾语的从句叫宾语从句。
（1）He told me (that ）he would go to college the next year.他告诉我他明年上大学。
（2）I don’t know if there will be a bus any more.我不知道是否还会有公交车。
（3）Nobody knew whether he could pass the exam.没有人知道他是否会通过考试。
（4）Teachers were asking me whether I had gone there or not at that time.那时老师们在问我是否我曾经去过那里。
(5)Do you know who has won Red Alert game？你知道是谁赢得了红色警戒的游戏么？
(6)The book will show you what the best CEO should know.这本书会告诉你最好的执行总裁该了解什么。
（7）Have you determined whichever you should buy, a Motorola or Nokia call phone？
你决定好是买诺基亚还是摩托罗拉的电话了吗？
（8）Can you tell me if there any shop here?你能告诉我这里有商店吗？
（9）He didn’t tell me when we should meet again.他没有告诉我什么时候我们能再见面.
