what在从句中的翻译

This is what he did to me before .这里what指代的是This,这里的what是引导从句的
Can you tell me what did you do last night.
这里的what 是do的宾语,有什么的意思

看具体情况what he said他说过的话what he did他做过的事

只要是指代名词性的就行。