友情提示：本文共有 4990 个字，阅读大概需要 10 分钟。
实用英语语法
第二十四讲
名词性从句
名词性从句，不难理解，通俗点说就是一个句子（从句）在另一个句子（主句）中做主语、宾语、表语、同位语、介词宾语等，相当于名词的用法。名词性从句根据在句子中所做的成分又可分别称为主语从句、宾语从句、表语从句和同位语从句。
名词性从句通常由以下词汇连接：
连接代词 what/ whatever, who/ whoever, whom/whomever, whose, which/ whichever
Do you know whose jacket it is?
（whose 在宾语从句中做jacket 的定语）
连接副词 when/ whenever, where/ wherever, how/ however, why
连词 that, whether, if （是否）， as if , as though
连接代词和连接副词就是特殊疑问句的疑问词，不过从句要用陈述形式，千万别用疑问形式。
Please tell him when will the movie begin.
这是错误的。
1）连接代词what, who, whom, whose, which既起连接主句和从句的作用，也在从句中充当句子成分。也就是说它们引导主语从句、宾语从句、表语从句，但在从句中又做主语或宾语。
大家可以自己研究下，在下面例句中，连接代词在从句中都做什么成分：
What we can do is to wait.
我们能做的就是等待。
What surprised all of us is that the concert was called off.
令我们吃惊的是音乐会取消了。
Could you tell me what time it is?
你能告诉我现在几点吗？
You can find out what job will make you (the) happiest.
你会发现什么工作能使你最快乐。
I will do what I can to help you.
我会尽我所能帮助你。
The problem is what we can do to protect the environment.
问题是我们能做些什么来保护环境。
Who will take his place will be decided by the boss.
谁接替他的职位将由老板决定。
I wonder who is right, Jack or Jane.
我想知道谁是对的，杰克或简。
The old man can"t remember who knocked him down.
老人记不起是谁撞倒他的了。
Her parents will decide who/whom she is going to marry.
她的父母将决定她嫁给谁。
在从句中做宾语，传统上要用whom，但现代英语里，who用得很普遍。除非你很讲究，完全可以全用who。介词后面还是必须用whom.
Could you tell me to whom I shall speak?
你能告诉我该和谁说吗？
We don"t know whose it is.
我们不知道它是谁的。
We are not sure whose jacket it is.
我们不知道是谁的夹克。
Choose which you like best.
选你最喜欢的。
I want to know which restaurant is the best.
我想知道哪家餐馆最好。
whatever, whoever, whomever, whichever从句可能是名词性从句，也可能是让步状语从句：
Whatever he does succeeds. 主语从句
无论他做什么都会成功。
I shall do whatever he orders. 宾语从句
我将按他的命令去做。
Whatever he orders I shall do. 状语从句
他命令做什么，我就做什么。
Whatever happens, it"s us together and we"ll make it. 状语从句
不管发生什么，我们都会在一起，我们会成功的。
Whatever he says, just don"t believe a word! 状语从句
不管他说什么，都不要相信！
I"ll buy it from whoever owns it. 宾语从句
不管是谁的，我都会从他那买。
You can ask whoever you like. 宾语从句
你想问谁就问谁。
Whoever breaks the law will be punished. 主语从句
违法者将受到惩罚。
Whoever breaks the law, he will be punished. 状语从句
不管谁违法，都会受到惩罚。
Whoever gets up first, don"t wake the other. 状语从句
无论谁先起床，别吵醒另一个。
You can take whichever (books) you want. 宾语从句
你想买什么书都可以。
Whichever way you turn, you will get there. 状语从句
无论你走哪条路，都能到那里。
2) when/ whenever, where/ wherever, how/ however, why引导主语从句、宾语从句、表语从句，它们在从句中分别做时间状语，地点状语，方式状语和原因状语。
When the train is going to arrive is not informed.
火车什么时候到达没有通知。
No one knew when he left.
没有人知道他什么时候离开的。
Could you tell me where the bank is?
你能告诉我银行在哪儿吗？
How he went through the desert is still a mystery.
他是如何穿越沙漠的仍然是个谜。
We must study how The giant panda live in the wild.
我们必须研究大熊猫是如何在野外生活的。
I don"t care why he didn"t show up.
我不在乎他为什么不来。
I"ll go wherever you go - and I"ll be happy there.
无论你去哪里，我都会去的，而且我会呆得很开心。
However difficult it is, we are sure to finish it on time.状语从句
不管有多困难，我们一定要按时完成。
Whenever you were hungry, there is always something to eat.状语从句
每当你饿了，那总会有东西吃。
whenever, wherever, however也常常引导让步状语从句。
3) 连词 that（没有任何意义）, whether, if （是否）， as if, as though（似乎 ）
不在从句中充当句子成分，只有连接主句和从句的作用，也就是说它们说引导的句子是完整的，不缺必须的成分。它们引导主语从句、宾语从句、表语从句。同位语从句用that引导。
That each of us takes more bus can help reduce the air pollution. 主语从句（that 不能省略）
我们每个人多乘公共汽车可以减少空气污染。
I don"t think ( that ) he will agree with your idea.宾语从句（that 可以省略）
我认为他不会同意你的想法。
What makes us excited is that the famous writer will come and make a speech to us.（表语从句，that也可以省略）
让我们兴奋的是那位著名作家会来给我们做演讲。
that主语从句经常后置，用it做形式主语：
It is reported that seven people have been seriously injured in the accident.
据报道，事故中有7人重伤。
It"s said that a new manager will take his place.
据说新经理将接替他的职位。
It"s well known that Chinese people are hard working.
众所周知，中国人很勤劳。
It"s important that a person (should) be well educated.
一个人受过良好教育是很重要的。
You never know whether/if it"s going to rain tomorrow.
你永远不知道明天是否下雨。
I wonder whether/if I can stay for another day.
我想知道我是否能再呆一天。
What we are worried about is whether/if he can feel better soon.
我们担心的是他是否能很快好转。
只能用whether的情况：
在主语从句中不能用if，介词宾语一般也不用if,而且if一般不与or not搭配。
I don"t
Whether the game will be held tomorrow (or not) is up to the weather.
明天是否举行比赛取决于天气。
He is hesitating about whether he should tell her the truth.
他在犹豫是否应该告诉她真相。
It looks as if she is satisfied with her job.
看来她对她的工作很满意。
She felt as if all had gone wrong.
她觉得一切都出问题了。as if 比as though更常用
下面我们专门学习一下同位语从句
同位语是指对另一个名词或代词进行解释或补充说明的一个名词(或其它形式)。
同位语从句就是在句中作某些名词的同位语，对前面的名词进一步说明。常常跟同位语的名词有：
fact, news, idea, hope, thought, doubt. truth, order, suggestion等.
He was late for work for the reason that he misssed the first train.
他上班迟到是因为误了第一班火车。
he misssed the first train就是the reason
Despite the fact that it was raining hard, the football game continued.
尽管雨下得很大，足球比赛还是继续进行。
There is no doubt that you"ll make it.
毫无疑问，你会成功的。
They have no idea at all where their son has gone.
他们完全不知道他们的儿子去了哪里。注意：that从句在名词后面可能是同位语从句也可能是定语从句。
如果大家想区别的话，要看从句是否完整，从句完整，就是同位语从句；从句中缺少主语或宾语，就意味着that指代被修饰词，在从句中做主语或宾语，为定语从句。We read the news that some foreigners would visit our school. 我们看到一些外国人会来我们学校参观的消息。
I don"t think the news (that) he told us is true.
我不认为他告诉我们的消息是真的。
我们可以发现，同位语从句和定语从句的区别完全是句法上的区别。语义上，可以直接理解为定语的意思。
图片来自网络，版权为原作者所有
本文如果对你有帮助，请点赞收藏《实用英语语法 第二十四讲 名词性从句》，同时在此感谢原作者。
