• Brainly User
You tell him the proof like the time he was tearing the pages or what he was tearing then he will come to know that you really knew what he was doing the warn him tell him that you are doing wrong and if he does it again inform the librarian
First try to make him understand  books are our real friends.
books are our god.
each book is made out by each tree .
so if we tear pages from books , in one way we r killing trees that is we r harming ourselves . our duty to save trees .
and if he continues to tear pages again , its our duty to inform the incharge teachers of the library. becoz in one way we r saving the life of a tree. n in anthr way we r saving all living organisms.
hope it can help u......