what引导宾语从句的具体用法如下:
作为宾语从句的主要成分:
He didn't know what to do.(他不知道该做什么。)
I can't remember what he said.(我记不得他说了什么。)
作为宾语从句的主语:
What he said surprised me.(他说的话让我感到惊讶。)
What she did was unforgivable.(她所做的是不可原谅的。)
作为宾语从句的补充成分:
I can't believe what he did.(我无法相信他所做的。)
She asked me what time it was.(她问我几点钟。)
作为宾语从句的宾语补足语:
They made it clear what they wanted.(他们明确表示了他们想要的东西。)
I don't know what to say.(我不知道该说什么。)
需要注意的是,what引导的宾语从句通常代替宾语的内容或情况,并在从句中充当某一成分,如主语、宾语、补充成分或宾语补足语等。