what引导从句用法例句

看从句在句子中做什么成分，what引导名词性从句，如主语从句，宾语从句，表语从句，同位语从句，它在从句中可以作主语、宾语、表语、定语、宾补。例如：Do you know what i did just now?(宾语从句）。

1.主语从句：What is beautiful is not always good.

美的东西并不总内是好的。

2.宾语从句：I could hardly believe what he had told me.

我简直不敢相信他所告诉我的。

3.表语从句：Books are what we need most.

书是容我们最需要的东西。

4.同位语从句：I have no idea what he is doing.

我不知道他正在做什么。