i don't know how to do next还是what to do next

i don't know how to do next还是what to do next
i don't know how to do next还是what to do next

i don't know how to do next还是what to do next
what.在这里what用来做do的宾语.
how这个词是不能做宾语的,所以要用how的话,do 后面还要加上一个宾语,比如it.

what 2 do next

用what
表示下一步做”什么”
而how是表示”方式”