高考英语——名词性从句
高中英语名词性从句是高考考查的重点，包括主语从句、宾语从句、表语从句及同位语从句。下面来进行一一讲解。
名词性从句（1）主语从句
1. 定义：用作主语的从句叫做主语从句。 2. 构成：关联词+简单句
3.引导主语从句的关联词有三类： (1) 从属连词that。
如：That they were in truth sisters was clear from the facial resemblance between them. 很明显，她们确是亲姐妹，她们的脸型很相似。
(2) 从属连词whether。
如： Whether he’ll come here isn’t clear. 他是否会来这里还不清楚。
(3) 连接代词who, whom, whose, what, which, whoever, whatever, whichever 连接副词 where, when, how, why。 如： What she did is not yet known. 她干了什么尚不清楚。
How this happened is not clear to anyone. 这事怎样发生的，谁也不清楚。 Whoever comes is welcome. 不论谁来都欢迎。
Wherever you are is my home ---- my only home. 你所在的任何地方就是我的家----我唯一的家。
解释： 1. 主语从句能用it作形式上的主语。常以it作形式主语的句型有：
A. It+be+形容词(obvious, true, natural, surprising, good, wonderful, funny, possible, likely, certain, probable, etc.)+that从句。如： It is certain that she will do well in her exam. 毫无疑问她考试成绩会很好。 It is probable that he told her everything. 很可能他把一切都告诉她了。 B. It+be+名词词组(no wonder, an honour, a good thing, a pity, no surprise, etc.)+that从句。如： It’s a pity that we can’t go. 很遗憾我们不能去。 It’s no surprise that our team should have won the game. 我们没赢这场比赛真意外。
C. It+be+过去分词(said, reported, thought, expected, decided, announced, arranged, etc.)+that从句。如： It is said that Mr. Green has arrived in Beijing. 据说格林先生已经到了北京。 It is
reported that China has sent another man-made earth satellite into orbit. 据报道中国又成功地发射了一颗人造地球卫星。
D. It+seem, happen等不及物动词及短语+that从句。如： It seems that Alice is not coming to the party at all. Alice似乎不来参加晚会。 It happened that I was out that day. 碰巧我那天外出了。
E. It+doesn’t matter (makes no difference, etc.)+连接代词或连接副词引起的主语从句。如： It doesn’t matter whether she will come or not. 她是否来这无关紧要。 It makes no difference where we shall have the meeting. 我们在哪里开会毫无区别。
F. 当that引导的主语从句出现在疑问句中时，要以it作形式主语，而把主语从句后置。如： Is it true that the scientist will give us a lecture next week? 下周那位科学家将给我们作报告是真的吗? Does it matter much that they will not come tomorrow? 他们明天不来很要紧吗?
G. 当主语从句出现在感叹句中时，要以it作形式主语，而把主语从句后置。如： How strange it is that the children are so quiet! 孩子们这么安静真奇怪! 2.注意连接代词whoever, whatever, whichever等引导主语从句的含义 Whoever comes will be welcome. (whoever=the person who) 来的人将受到欢迎。 Whatever he did was right. (whatever=the thing that) 他所做的事情是正确的。 Whichever of you comes in will receive a prize. (whichever=anyone of you who) 你们当中不论哪个进来将会得到奖
名词性从句（2）宾语从句
宾语从句是一种名词性从句，在句中作及物动词的宾语，或介词的宾语，或形容词的宾语。根据引导宾语从句的不同连词，宾语从句可分为三类。
1. 由that引导的宾语从句。That只有语法作用，没有实在的意义，在口语和非正式文体中可以省略。例如：
He said (that) he wanted to stay at home.他说他想呆在家里。 She doesn’t know (that) she is seriously ill.她不知道她病得很严重。 I am sure (that) he will succeed.我确信他会成功。
2. 由连接代词who, whom, whose, what, which和连接副词when, where, why, how引导的宾语从句。这些连接代词和连接副词在宾语从句中充当某个成分。例如： Do you know who (whom) they are waiting for? 你知道他们在等谁吗？ He asked whose handwriting was the best.他问谁的书法最好。
Can you tell me where the No.3 bus stop is? 你能告诉我3路公共汽车站在哪儿吗？ I don’t know why the train is late.我不知道火车为什么晚了。
I can't imagine why he did that thing．我不能想像他为什么做了那件事。
Do you know why we have put off the sports meet till next month? 你知道我们为什么把运动会推迟到下个月吗?
以上两个例句的宾语从句相当于一个特殊疑问句，分别为：why did he do that thing?和Why have you put off the sports meet till next month?由于宾语从句要求陈述句语序，故而在从句中它变成了陈述语序。请看下列两组句子：
How much does this coat cost? 这件衣服值多少钱?
I want to know how much this coat costs．我想知道这件衣服值多少钱。 Where did you go yesterday? 你昨天去哪儿了?
Please tell me where you went yesterday．请告诉我你昨天去哪儿了。
当疑问代词what，who在特殊疑问句中做主语时，该特殊疑问句本身就是陈述句语序，所以当该句用来做宾语时，语序不需要调整。 What's wrong with you? 怎么了?
He asked the girl what was wrong with her．他问这个女孩怎么回事了。 What's the matter? 怎么了?
He asked the girl what was the matter．他问这个女孩怎么了。 What has happened to him? 他发生什么事了?
We want to know what has happened to him．我们想知道他发生了什么事。 同类句式还有：Who broke the window? 谁打破的窗户? Who is in the classroom? 谁在教室里?
What made him so angry．什么使得他如此生气。
3. 由if或whether引导的宾语从句。表示“是否”，二者通常可以互换。例如： Lily asked if/whether she liked it.莉莉问她是否喜欢它。
I want to know if (whether) he lives there.我想知道他是否住在这儿。 He asked me whether (if) I could help him.他问我是否可以帮助他。 但语义有点区别：
1）whether强调犹豫和选择，多见于书面语中；if 只限于条件，常用于口语。例如：