i don't know how to do it句型转换i don't know[ ][ ][ ]do.

i don't know how to do it句型转换
i don't know[ ][ ][ ]do.

how i can

how I should

how do i

i don't know how I can do.

what I can

what i can

i don't know what can i do

what can I do ?
如果用how I can do 也行
how do I 明显不行