对so that引导的句子提问用什么

很高兴为你
so that 引导的是目的状语从句,意思为:为了,提问要用为什么?
Why did he get up so early
What did he get up early for
For what did he get up so early
What was the reason for his getting up early
他为什么起那么早?
why = what for 为什么
祝开心~!