正常译法是i don't know what to do ,为什么不能用i don't know how to do

问题描述:

正常译法是i don't know what to do ,为什么不能用i don't know how to do
what 是引导宾从的,难道就是这个原因吗,这句话缺少宾语,所以就用what?但是感觉how 也挺合适的呀?

I don't know what to do.
what 是疑问代词,疑问词+动词不定式 在句中作宾语,what又作do的宾语.而how是疑问副词,不能作do的宾语,如果用how的话,后面要加宾语才完整,一般加it.