英语语法填空的疑问.I can’t give you that for nothing,what do you take

I don't know what I can do for you 为什么用what不用that 英语翻译来自《加勒比海盗》Take what you can.Give nothing back. Do you know what I'm going to give you for your birthday?小疑问 you can do what i can never do.you don't give up what can I do for you?--------------- A.yes,you can give me You can give me that he can't,that's what I really need nothing you can do that can't be done what ----- can i do for you --nothing 用else还是another Mom,what can I do for you?Nothing else.( ) is OK what do you want,i can give you! i will take all that you can give us. I don't know what can i do for you.but i missing you so much