学习表语从句五大要素

学习表语从句五大要素

表语从句位于连系动词之后，引导表语从句的词有that, what, how, when,where, why, because, as if 等。要掌握好表语从句，我们在学习中必须要注意下面这些要点：

一、表语从句要用陈述语序。如

This is where the famous scientist was born.

This is why she is so happy today.

二、that和what在引导表语从句时，作用和意义都不一样。That 本身没有词义，在句中仅起连接作用，而不充当句子成分；what 则表示“所...的（人或事）”，在表语从句中充当主语或宾语等。如：The fact is that more than seventy percent of the earth’s surface is covered by water.(that 不作句子成分)

What he told you was what had been discussed at the meeting.(第一个what 作主句中的宾语；第二个what 在表语从句中主语)。

三、if 与whether 均意为“是否”，但引导表语从句时，只能用whether,不用if

The question is whether we can finish our work by tomorrow evening.

四、当主句的主语为reason，或者是由Why 引导的从句时，与它们相关的表语从句的连接词多用that.如：

Why she failed in physics exam was that she was too careless.

五、as if, as through 引导表语从句时，从句谓语常用虚拟语气。这是

因为从句中的情况与事实不符。具体来说，如果从句表示与现在事实相反，谓语动词用一般过去式；如果从句表示与过去事实相反，谓语动词要用“had+过去分词”，如果从句表示将来的可能性不大，用would (might,could)+ 动词原形。如：

Lilei is now in a new jacket. He looks as if he were an American boy.

The girl is giving us a vivid description of the moon. It seems as if she had been to the moon many times.

It looks as if it might rain

但是，如果as if ,through 引导的表语从句所表示的情况与事实相符，从句则用陈述语气。如：

The cloud are gathering. It looks as if it is going to rain.

That 与what从句浅谈

That 与what 从句是中学课本中的一项重要语法，也是学生容易出错的地方，现将其用法归纳如下：

一、引导主语从句

That 与what 都可以引导主语从句，that 在从句中不作句子成份，但不能省略。What 在从句中可作主语、宾语、表语等，不能省略。如：

What he said at the meeting was very important.

他在会上说得非常重要（what 在主语从句中作宾语）

What surprised us that he did it alone.

使我们吃惊的是他一个人做了那项工作。（what 在主语从句中作主语）。

That he did it alone surprise us.

他独自完成了那项工作使我们感到吃惊。（that 用来引导主语从句，在句中不用成份）。

二、引导宾语从句

That 与what 都可以引导宾语从句，that 在句中不作句子成份，一般情况可以省略，但当有两个以上的宾语从句时，只能省掉一个that. What 在从句中作主语、表语、宾语等，不能省略。如：They stopped to see what was happening.

他们停下来看发生了什么事情。（what 在宾语从句中作主语）。

The teacher got angry because of what the boy had done.

那个男孩子做的事情让老师很生气。（what在宾语从句作宾语）All the people believe (that )it was right to rescue the temple.

所有人都认为拯救古庙是正确的。（that 在宾语从句中不作句份，可以省略）

We must believe (that ) each one of us is able to do something well, and that, when we discover what this something is , we must work hard at it until we succeed.

我们必须相信，我们每个人都能把某些事情做好；而且，当我们发现这些事情是什么的时候，我们就必须努力干下去，直到成功为止（第

一个that 可以省略，第二个that 不能省略）。

三、引导表语从句

That 与what 都可以引导表语从句，that 在句中不作句子成份，且不能省略；what 在从句中作主语、宾语、表语，但不能省略。如：Mary is no longer is what she used to be. 玛丽不再是从前那样了（what 在表语从句中作表语）。

The question is what we should do to prevent him from going .

问题是我们做什么才能阴止他进来（what在表语从句中作动词do的宾语）

The reason why he didn’t come today is that his mother is ill.

他今天没有来的原因是他母亲病了（that 只起连接作用）。

四、引导同位语从句

That 与what 都可以引导同位语从句修饰表示抽象概念的名词，对所修饰的名词的具体内容进行详细阐述。这类名词有：face, idea, news, hope, belief, promise, though, suggestion, proposal等。That在句中不用句子成份，但不能省略。What 在句中可以做主语、宾语、表语等，但不能省略，如：

I have no idea what we should do next.

我不知道我们下一步该做什么。（what 在同位语从句中作宾语）

He made a promise that he would study hard.

他许诺在努力学习（that 只起连接作用）。

The boy expressed his hope that he would be a pilot when he grows up.