高考英语一一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—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:⑴从属连词that。
女口：That they were in truth sisters was clear from the facial resemblanee 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 ' II come here isn '他是否会来这里还不清楚。
(3)连接代词who, whom, whose, what, which, whoever, whatever, whichever 连接畐词where, when, how, why。
女口：What she did is not yet kn ow n.她干了什么尚不清楚。
How this happe ned is not clear to anyon e.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 everyth ing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 pityiat we can ' t g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 isreported that Chi na has sent ano ther 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 comi ng 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 matt(makes no differenee, etc.)+连接代词或连接副词引起的主语从句。
如：It doesn' matter whether she will come or not.她是否来这无关紧要。
It makes no differenee where we shall have the meeti ng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 scie ntist will give us a lecture n ext 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：Howstrange 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 thi ng that)他所做的事情是正确的。
Whichever of you comes in will receive a prize. (whichever=a nyone 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 wan ted to stay at hom他说他想呆在家里。
She doesn ' t know (that) she is seriously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 和连接畐U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 kn ow who (whom) they are waiti ng for?你知道他们在等谁吗?He asked whose han dwrit ing was the besttfc 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 la我不知道火车为什么晚了。
I can't imagi ne 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 n ext mon th? 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Whyhave you put off the sports meet till next mon th?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 we nt 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 he. 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 happe ned 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 an gry 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) whethe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: Write and tell me whether rm to come.请写信告诉我，我是否该来。
Write and tell me if rm to come.如果我该来，请写信告诉我（相当于说：若我不必来，那就不用费心写信给我了。
）2）whethe可引导各种名词性从名和让步状语从句，if只能引导宾语从句和条件状语从句。
由if引导的从句，首先要弄清楚是宾语从句，还是条件状语从句，然后再确定时态。
若是弓丨导条件状语从句，谓语动词应用一般现在（过去）时代替一般将来（过去将来）时。
___ 例如：If you don't go soon, you '如果你不.马上去就会迟到。
当if引导一个非真实条件句时，从句的谓语动词应用过去式（如果是be,则不论主语的人称和数，一律用were）,主句谓语动词用“would动词原形”例如：If every one in the country knew first aid, many lives would be saved 如果每个国民都懂得急救（的知识），许多生命就会得以挽救。