i have to leave in a while but i'll be back tonight or i am going to be back tonight. Anything i can do for you? Can you correct the previous sentence for me, please?
I have to leave in a while but I will come back tonight. I can do anything for you.

It will help you.
the entire meaning changes vrushali, maj is asking a question "anything i can do?" and the reply "i can do anything for you" has a lot difference!
Maj: i'll be back is right
Students: We have free audio pronunciation exercises.
My original question was: Is there anything i can do for you? So what would you reply in this context?
no thanks! he he!