This is the 743rd most frequent Turkish word.
ona
"To him/her/it" or "to that."
In this sentence, 'ona' is used to mean 'to her' or 'to him', indicating the receiver of the action.
Ona bir hediye aldım.
I bought a gift for her/him.
Here, 'ona' is again 'to him' or 'to her', showing the indirect object receiving the questions.
Soruları ona sordum.
I asked him/her the questions.
In this instance, 'ona' means 'to her' or 'to him', indicating the person to whom the book will be given.