It is common knowledge that computers are super calculators .这句话是定语从句吗?那么that充当什么成分呢?

问题描述:

It is common knowledge that computers are super calculators .这句话是定语从句吗?那么that充当什么成分呢?

不是,It做形式主语,that引导的从句做真正主语。

主语从句
That computers are super calculators is common knowledge.

这句话不是定语从句 that后跟的是主语从句
it是形式主语
真正的主语是that computers are super calculators
还原后 是that computers are super calculators is common knowledge .
为了防止句子头重脚轻 才放到后面的

不是,这是同位语从句
that是连接词,引导同位语从句,起到解释说明knowledge的作用