名词性从句九大高考热点分析
名词性从句包括主语从句、宾语从句、表语从句和同位语从句。因为它是从句，因此具有句子的结构特点（即有一套主谓成份）；同时又具有名词性特点，所以可以在复合句中作主语、宾语、表语或同位语。名词性从句是中学英语学习的重点，也是高考的主要考点之一。我们必须弄懂和掌握以下热点问题。
一、连接词what与that的用法区别
引导主、宾、表语从句时，what要充当主语、宾语或表语等句子成分，that不作任何成分，只在语法上起连接的作用。例如
____ we can’t get seems better than ____ we have.
A. What; what B. what; that C. That; that D. That; what
解析：本句包含一个主语从句和一个宾语从句，且两个从句都缺乏宾语，可见两个引导词都必须充当成分，所以答案是A。又如：
____ caused the accident is still a complete mystery.
A. What B. That C. How D. Where
解析：该题答案是A，what在主语从句中作主语，即作谓语动词caused的执行者。在下面的例句中，that不充当任何成份，只起语法连接作用（因为句子本身不缺成分）：
That the former Iraq president Saddam was captured has been proved.
二、 连接词whether和if的用法区别
通常，引导主语从句、表语从句和引导同位语从句时，要用连词whether，不用if；习惯上也只能说whether or not，而不说if …or not。例如：
____ the 2000 Olympic Games will be held in Beijing is not known yet.
A. Whenever B. If C. Whether D. That
解析：试题中的从句位于句首，不难知道这是一个主语从句，所以答案是C。但是在宾语从句中表达“是否”既可用if也可用whether。
三、 名词性从句的语序
与别的从句一样，名词性从句必须用陈述语序。例如:
No one can be sure ____ in a million years.
A. what man will look like B. what will man look like
C. man will look like what D. what look will man like
解析：由于从句不能倒装，所以答案只能是A。又如：
You can’t imagine ____ when they received these nice Christmas presents.
A. how they were excited B. how excited they were
C. how excited were they D. they were how excited
解析：答案是B。同时还须注意，从句的引导词必须始终置于句首，而且how和被修饰的词excited不能分裂开。
四、 形式主语、形式宾语
当主语从句较长，而谓语较短时，常常将从句后置，而用it作为形式主语，置于句首。
动词后接复合宾语，也可用it作形式宾语。例如:
____ is a fact that English is being accepted as an international language.
A. There B. This C. That D. It
解析：所需词至于句首，同时后面有that-从句（逻辑主语），可见这里应该用形式主语it,所以答案是D。think, find, consider, believe, feel等动词后常带复合宾语。例如：
Many people think it possible that a trade war between EU and the States will happen.
五、 Who / whoever, what / whatever等的用法区别
一般说来，what/who等含特指意义，而whatever/whoever等含泛指意义，意为“无论什么/无论谁”。例如：
It is generally considered unwise to give a child ____ he or she wants.
A. however B. whatever C. whichever D. whenever
解析：答案是B，whatever引导一个宾语从句，并且作wants的宾语。这里的whatever不能改成what，因为题意想表达的显然是“无论孩子要什么就给他/她什么事不明智的”，具有泛指的概念。同时要注意，这里whatever也不能改用no matter what，因为后者只能引导状语从句。又如：
____ has helped to save the drowning girl is worth praising.
A. Who B. The one C. Anyone D. Whoever
解析：答案是D，whoever意为“无论谁”，表泛指。比较下例：
I can’t remember at the moment who has said the words. （这里的who表特定的某人）
六、 Where, when, why等连接副词引导的名词性从句
Where, when, why等连接副词也可以引导名词性从句，使用的关键是：这个词必须符合句子的逻辑意义要求。例如：
— I drove to Zhuhai for the air show last week.
— Is that ____ you had a few days off?
A. why B. when C. that D. where
解析：答案是A，why引导的从句作表语，同时why在从句中作原因状语。这里之所以选why，而不是when或 where等，唯一的依据便是句子的逻辑含义，及语境。又如（MET94）；
—Do you remember ____ he came?
—Yes, I do, he came by car.
A. How B. when C. that D. if
解析：答案是A，从答语 “he came by car”可知这里问的是“he”来的方式，所以用how引导。
七．“介词+who(m)引导的宾语从句”与“介词+ whom”引导的定语从句的区别
介词后面的引导词用主格还是宾格，决定于它在宾语从句中作主语还是宾语。例如：
It was a matter of ____ would take the position.
A. who B. whoever C. whom D. whomever
解析：答案是A。这是一个含宾语从句的复合句，作介词of宾语的，是后面的整个句子，而不是宾语从句的引导词，由于这里引导词在从句中作主语，所以要用主格who（作宾语时自然要用whom）。比较下例：
Our country has thousands of excellent scientists, most of whom have received higher education at home.
这是一个“介词+关系代词”引导的定语从句；引导定语从句的是“most of+关系代词”而不只是这个关系代词，同时这个引导词又作介词of的宾语，所以要用宾格whom。（注意与介词后面的宾语从句的引导词的用法进行比较和区别。）
八、连接词that的省略
引导宾语从句时，that通常可以省略，但引导主语、表语和同位语从句时，that不能省。例如：
China’s success in manned-spacecraft travel shows ____ our country has become one of the greatest powers in space research.
A. what B. which C. 不填 D. it that
解析：该句中的从句作shows的宾语，是宾语从句，又因为从句中不缺主、宾语，所以只能用that引导；又因引导宾语从句时that可以省略，所以答案是C。
九、同位语从句引导词where, when的用法特点
说明先行词内容的同位语从句的引导词where, when与被说明的名词在概念上不一致。但引导定语从句的引导词却必须保持一致。是比较：
Then arose the question ____ we were to get so much money.
This the house ____ the great man Mao Zedong was born 110 years ago.
A. where B. that C. about which D. in which
解析：答案分别是(1) A (2) A/D。先行词与where, when概念一致时，是定语从句，（2）中的house与where同表地点，且这个关系副词where或when可以用“介词+which”的形式代替，所以答案A 和D都可以引导。（1）题中的question与where不表同一概念，可见是同位语从句，所以where不能改用“介词+which”的形式。
