主语从句与表语从句
【考点导航】
1. It is obvious to the students ______ they should get well prepared for their future.
(2009天津)
A. as B. which C. whether D. that
2. The last time we had great fun was _____ we were visiting the Water Park. （2008天津）
A. where B. how C. when D. why
[答案与解析] 1. D。that引导的从句在句子中起真实主语的作用，it是形式主语。2. C。本句考查表语从句的用法。when we were visiting the Water Park 是表语从句。
【重点归纳】
主语从句和表语从句属于名词性从句；名词性从句还包括宾语从句和同位语从句。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。下面分别讲解主语从句和表语从句。
一、主语从句
用作主语的从句叫主语从句，引导主语从句的关联词有三类：
1. 从属连词that。如：
That they are in truth friends is obvious.
2. 从属连词whether。如：
Whether he’ll visit our company hasn’t been decided yet.
3. 连接代词who, whom, whose, what, which, whoever, whatever, whichever；连接副词 where, when, how, why。如：
What he did really satisfied us all.
表语从句
表语是用来说明主语的身份、性质、品性、特征和状态的。表语从句在复合句中作表语的名词性从句，一般结构是“主语＋连系动词＋表语从句”。
引导表语从句的that常可省略。另外，常用的还有the reason is that… 和It is because 等结构.
表语常由名词、形容词、副词、介词短语、不定式、动词的-ing、从句来充当，它常位于系动词（be, become, appear,
seem,look,sound,feel,get,smell等词）之后。
连系动词：be动词、表示持续的系动词（keep, remain, stay）、感官动词feel(摸起来，感觉) , smell(闻起来) , sound(听起来) , taste(尝起来，吃起来) 等、表示变化的系动词（become, grow, turn, fall, get, go,）、表终止的系动词prove, turn out(结果是，证明是)、seem,
appear（看起来···）
连系动词通常不用于被动语态和进行时态中。
He has become what he wanted to be ten years ago. 他已经成为了他10年前想成为的。
His suggestion is that we should stay calm. 他的建议是，我们应该保持冷静。
如果句子的表语也是由一个句子充当的,那么这个充当表语的句子就叫做表语从句。构成：关联词+简单句
一 定义：
A 表语从句就是用一个句(在复合句中)作为,充当表语,说明主语是什么或者怎么样，总之表语是对主语的解释和说明，是主语具体化，并且常与连系动词一起使用。由名词、形容词或相当于名词或形容词的词或短语充当，和连系动词一起构成谓语。，它位于主句中的连系动词之后。
This book looks expensive. (形容词做表语) We are Chinese. (名词做表语) The problem is puzzling. 主语 连系动词 形容词作表语 The problem is when we can get a pay rise. 主语 连系动词 一个句子作表语---表语从句
1 表语从句练习
1.这就是我想做的 2.这房子正是他最需要的东西。
3.问题在于人们怎样才能找到一种有效的方式来储藏太阳热。
4.问题是谁能完成这项困难的任务 5.今天讨论的话题是未来的学校会是怎样的
6.他迟到的原因是交通拥堵. 7.事实是他对我撒谎了. 8.这就是Henry 怎样解决问题的
1. The question is ________ we will have our sports meet next week.
A. that B. if C. when D. whether
2．The reason why he failed is ________he was too careless.
A. because B. that C. for D. because of
3. Go and get your coat. It’ s ________you left it
A. where B. there C. there where D. where there
4．The problem is _________to take the place of Ted
A. who can we get B. what we can get C. who we can get D. that we can get
5. What I want to know is ______ he likes the gift given by us.
A. that B. if C. whether D.不填
6. The reason is_________I missed the bus.
Predicative Clauses
表语从句
一、 什么是表语从句
先看两个句子：
The question is difficult.
（表语）
The question is who will do it.
（表语从句）
★定义：
表语从句在复合句中作主句的表语。表语从句和主语指同一内容，它对主语进行解释、说明，使主语的内容具体化。
★结构：
主语+系动词+表语从句
↓↓
（引导词 + 简单句）
★常见的可以接表语从句的系动词有：
be, look, remain, seem等。
★从句引导词：
连接词：that / whether /as if /as though
连接代词：who / whom / whose / which / what
连接副词：when / where / why / how / because
EXAMPLES:
主语 + 系动词 + 引导词 + 简单句
↓ ↓ ↓ ↓
1. The question is whether we can rely on him.
2. He looked as if he was going to cry.
3. That is why I was late.
二、引导词的用法
That:
（1）that在表语从句中既不充当成分,又没有意义。
The fact is that he hasn’t yet recovered from illness.
