什么叫表语

句子的表语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
The fact is that he was cheated.
这是个系表结构的句子,the fact是主语,谓语是系表结构,表语是that he was cheated,这个that引导的句子就是表语从句.

宾补和双宾的区别先看下面两个句子
They elected him president.
I sent him a telegram.
第一个句子里面的him是elect的宾语,而president则不是elect的宾语,它是补充说明宾语him的情况.
第二个句子里面的him 依然是send的宾语,而telegram也是send的宾语
表语从句

一 定义：

A 表语从句就是用一个句子作为表语。

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

B 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.

He has become what he wanted to be ten years ago.

She has remained there for an hour.

She has remained where I stood yesterday for an hour.

His suggestion is good.

His suggestion is that we should stay calm.

The question is confusing.

The question is when he can arrive at the hotel.

who will travel with me to Beijing tomorrow.

why he cried yesterday.

how I can persuade her to join us in the party.

whether the enemy is marching towards us.

二 注意：

A 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.

B 不可以用if，而用whether 连接表语从句(as if 例外）。

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.

C 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.

D that在表语从句中不可以省掉。

表语
表语
表语是用来说明主语的身份、特征和状态的，它常位于联系动词（be, become, appear, seem等）之后。
一. 名词作表语

Africa is a big continent.

非洲是个大洲。

That remains a puzzle to me.

这对我还是个难题。

二. 代词作表语

What’s your fax number?

你的传真号是多少？

三. 形容词作表语

I feel much better today.

我今天感觉好多了。

四. 数词作表语

She was the first to learn about it.

她是第一个知道的人。

五. 不定式或ing形式作表语

Her job is selling computers.

她的工作是销售电脑。

Our next step was to get raw materials ready.

我们下一步是把原料准备好。

六. 介词短语作表语

The patient is out of danger.

病人脱险了。

I don’t feel at ease.

我感到不自在。

七. 副词作表语

The sun is up.

太阳升起来了。

I must be off now.

现在我得走了。

八. 从句作表语

This is what he said.

这就是他所说的话。
不定式作表语

作表语的不定式短语通常是说明主语的内容，这时主语通常是如下名词：
hope, idea, job, plan, wish, aim, purpose, thing, business

<><><>

The purpose of new technologies is to make life easier, not to make it more difficult.

新技术的目的是使生活更便利，而不是更繁琐。

Her wish is to become a singer.

她的愿望是当一名歌手。

Our plan is to finish the work in two weeks.

我们的计划就是在两星期内完成这项工作。

表语从句

在句子中起表语作用的从句叫做宾语从句。表语从句的引导词和主语从句的引导词相同。
What the police want to know is when you entered the room.

警察想知道的是你什么时候进的房间。

The trouble is that we are short of funds.

困难是我们缺乏资金。

This is what we should do.

这是我们应当做的。

That's why I want you to work there.

那就是我要你在那儿工作的原因。

His first question was whether Mr. Smith had arrived yet.

他的第一个问题是史密斯先生到了没有。

<><><>

as if, as though, because也可用来引导表语从句。

She seems as if she had done a great thing.

她看起来好像做了一件大事。

It is because you eat too much.

那是因为你吃得太多了。

ing形式作表语

ing形式作表语表示泛指意义的动作，不定式作表语表示一次性的动作。
My hobby is growing flowers.

我的爱好是种花。

My favourite sport is playing tennis.

我喜爱的运动是打网球。

<><><>

比较：

What I am going to do is to play tennis this afternoon.

我今天下午要做的事是打网球。

ing形式作表语：注意事项

在句型"主 + 系 + 表"中，若主语和表语都是非谓语形式时，主语和表语要取得一致。如：主语
是ing形式表语也应是ing形式，主语是不定式时表语也应是不定式。

<><><>

Seeing is believing.

To see is to believe.

眼见为实。

<><><>

(误) Seeing is to believe.

ing形式作定语

ing形式可以作名词的前置定语，ing形式短语作后置定语。
<><><>

ing形式作前置定语

a swimming pool

a teaching method

<><><>

ing形式短语作后置定语

Do you know the man standing at the entrance?

你认识站在入口处的那个人吗？

There were a lot of people boating on the lake.

湖上有许多正在划船的人。

虚拟语气：表语从句

主语是idea, notion, proposal, suggestion, request等名词时,
作表语从句的动词为原形动词或should+原形动词。

My suggestion is that we (should) go and help him.

我的建议是我们应该去帮助他。

Our only request is that this should be settled as soon as possible.

我们唯一的请求就是尽快解决这个问题。

表语是说明主语身份，职业，性质，状态或特征的句子成分，它只能与 sein, werden,
bleiben, scheinen, heissen 这些联系动词连用：

可做表语的词类和形式

1- 名词或代词

Sie ist Krankenschwester.
她是护士。

Das ist es gerade!
正巧是这么回事儿。

2- 副词

Die Zeit ist um.
时间到了。

3- 形容词，分词，数词

Sie ist sehr schoen.
她好漂亮。

Durch Krankheit verhindert, musste der Saenger das Konzert verschieben.
由于生病，歌唱家只好将此音乐会改期。

4- 第二格和第四格名词

Er hat den ganzen Tag in der Fabrik gearbeitet.
他在工厂工作了一整天。

Eines Tages schlug ein Blitz in unser Haus ein.
一天，闪电打到我家的房子上。

5- 不定式短语

Statt dies mit Worten zu schildern, zeige ich dir Bilder.
如其用语言来描述，还不如我给你看图片。