表语从句放在连系动词之后，充当复合句中的表语。表语从句(PredicativeClause)就是指一个句子作为表语，说明主语是什么或者怎么样，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。表语从句的构成是关联词+简单句。下面是高中英语表语从句讲解及专项练习，供参考。
高中英语表语从句讲解
1.表语从句:就是用一个句子作为表语。说明主语是什么或者怎么样，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。
Eg:The problem is puzzling.这问题令人困惑
主语 连系动词 形容词作表语
The problem is when we can get a pay rise.问题是什么时候我们可以得到加薪.
主语 连系动词 一个句子作表语---表语从句
2.连接表语从句的连接词有：that, what, who, when, where, which, why, whether,how.
He has become a teacher.他已经成为一名教师。
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。
She has remained there for an hour.
她曾在那里停留了一个小时。
She has remained where I stood yesterday for an hour.
她一直在我昨天站的地方站了一个小时。
His suggestion is good.他的建议是好的。
His suggestion is that we should stay calm.
他的建议是，我们应该保持冷静。
The question is when he can arrive at the hotel.
问题是，他什么时候可以到达酒店。
who will travel with me to Beijing tomorrow.
谁与我明天将前往北京。
why he cried yesterday.昨天他为什么哭。
how I can persuade her to join us in the party.
我怎么能说服她加入我们的派对。
whether the enemy is marching towards us.
是否敌人正向我们行进.
高中英语表语从句专项练习
表语从句练习题及答案
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.
A.that B.when C.why D.what
7.That is __ ___ we were late last time.
A.that B.when C.why D.what
8.She looked _________ she were ten years younger.
A.that B.like C.as D.as though
9.—I fell sick!
--I think it is _______ you are doing too much.
A.why B.when C.what D.because
10.The reason why he hasn’t come is ___________.
A.because his mother is ill B.because of his mother’s being illp分页标题e
C.that his mother is ill D.for his mother is ill
11.—He was born here.
-- That is _______ he likes the place so much.
A.that B.what C.why D.how
12.That is ______ Lu Xun once lived.
A.what B.where C.that D.why
答案：DBACCACDDCCB
that/what的区别练习题及答案
1._______your father wants to know is________ getting on with yourstudies.
A.What; how are you B.That;how you are
C.How;that you are D.What;how you are
2.The trouble is__________we are short of tools.
A.what B.that C.how D.why that
3.America was __________was first called “India” by Columbus.
A.what B.where C.the place D.there where
4.China is becoming stronger and stronger.It is no longer_________ .
A.what it used to be B.what it was used to being
C.what it used to being D.what it was used to be
5.________he really means is ________he disagrees with us.
A.What … that B.That … what
C.What … what D.That … what
6.The energy is ________ makes the cells able to do their work.
A.that B.which C.what D.such
that/what的区别答案：DBAAAC
高考英语表语从句真题及答案
1 —I drove to Zhuhai for the air show last week .
—Is that_____ you had a few days off?
A.why B .what C.when D.where
2 .I had neither a raincoat nor an umbrella ____I got wet through.
A.It’s the reason B.That’s why C.There’s why D.It’s how
3.See the flags on top of the building? That was ______ we did thismorning.
A.when B.which C.where D.what
4.--- Are you still thinking about yesterday’s game?
---Oh, that’s _____.
A.what makes me feel excited B.whatever I feel excited about
C.how I feel about it D.when I feel excited
5.What surprised me was not what he said but ______ he said it.
A.the way B.in the way that C.in the way D.the way which
答案：ABDAA
高中英语表语从句须注意
1.表语从句一定要用陈述语序。
False: The question is when can he arrive at the hotel.
Right: The question is when he can arrive at the hotel.
2.不可以用if，而用whether 连接表语从句(as if例外)。
引导宾语从句时可以互换if/whether 位于介词后要用whether，位于句首时要用whether引导表语从句，主语从句，同位语从句时要用whether
False: The question is if the enemy is marching towards us.
Right: The question is whether the enemy is marching towards us.
Right: It looked as if he had understood this question.
3.不像宾语从句，在有表语从句的复合句中，主句时态和从句时态可以不一致。
Right: The question is who will travel with me to Beijing tomorrow.
Right: The question is why he cried yesterday.
4.that在表语从句中不可以省掉。
表语从句的基本用法:
表语从句只能置于主句之后，而主句的动词只能是联系动词。
名词性从句在be等系动词后作表语时被称为表语从句.p分页标题e
例如：The problem is how we can get the things we need.(how 在表语从句中充当方式状语)
问题是我们怎样能弄到我们需要的东西。
The scissors are not what I need.(what 在表语从句中充当宾语)
这把剪刀不是我所需要的。
What I told him was that I would find him a good play.
我告诉他的是我会给他找个好剧本。(what在主语从句中作直接宾语，that作为表语从句的引导词在该表语从句中不充当句子成分，不能省略)
That is what I want to tell you.(what在表语从句中充当直接宾语)
那就是我想要对你讲的。
That is why she failed to pass the exam.(why在表语从句中充当原因状语)
那就是她考试不及格的原因。
注意：“That is why...”是常用句型， 意为“这就是……的原因/因此……”， 其中why引导的名词性从句在句中作表语，该句型通常用于针对前面已经说明过的原因进行，又如： That is why you see this old woman before you know,Jeanne.(前文提到Jeanne对老妇人显得苍老憔悴深感诧异， 说话人对她讲述了其中的原因之后，用这一句来进行概括)。
That is why I came.这就是我来的原因。
表语从句与宾语从句的关系
宾语从句和表语从句都属于名词性从句。其作用跟名词在句中的作用相同。故充当宾语的句子叫宾语从句，充当表语的句子叫表语从句。
宾语从句
(1)对于宾语从句要掌握以下三点
①语序:从句的语序必须是陈述句语序,即“主语+谓语”这种形式。
②时态:当主句是一般现在时或一般将来时的时候,从句可以是任何时态,而当主句是一般过去时的时候,从句,从句时态必须是过去时范围的时态,即(一般过去时,过去进行时,过去完成时,过去将来时)。
③连接词:当从句意思完整,主句意思肯定时,连接词用that,且可以省去,当从句意思完整,主句意思不确定或含否定含意时,常用if或whether(是否), 当从句意思不完整时, 连接词则是代替不完整部分的特殊疑问词。
