、what引导宾语从句

首先理解what的意思，最基本的就是“什么”。……的人/事/物。what引导的宾语从句中，what即是引导词，也在句子中充当句子成分，有一定的意义，what不能够被省略。

He has got what he wants.他已经得到了他想要的东西。

I believe what he said.我相信他说的话。

We have had what we need.我们拥有了我们需要的东西。

二、what引导主语从句

由what引导的整个句子做主语，其中what也不可以省略，翻译为……的

What we needis time.我们所需要的就是时间。

What we can dois waiting.我们所能做的就等待。

What they will dohasn't been decided.我们将要做什么还没有决定下来。

三、what引导表语从句

由what引导的整个句子做表语，其中what也不可以省略。

That iswhat I need .那就是我们所需要的（东西）

The man is no longer what he used to be.这个男人不再像他从前那样了。

四、判断下列句子从句类型

Tell me what you heard.

What he said is right.

I want to know what you did yesterday morning .

What I need is his help.

That is what they need .

Do you understand what I told you