"I will give her the book tomorrow."
Translation:Eu vou dar o livro para ela amanhã.
Unfortunately, duolingo accepts just "literal" translations... most of time....
A/o replaces verbs that don't require preposition. Dar requires a preposition, so you need to use "lhe" (dar para + someone).
Thanks! Now it's absolutely clear for me that para ela is better)))) Cause I don't know what does -ei mean? I haven't met it before, my grammar level is still abaixo da mínimo. ))