" Giving Suggestion" in Conversation

I will give you an example about giving suggestion in conversation below:

Naora : why are you so sad today?
Julian : I have problem that i can not tell you now.
Naora : what is that?, you can tell me , may be i can help your problem
Julian : I borrowed Jane's book yesterday, and i lost it.
Naora : where did you read that book yesterday?
Julian : I read it in the canteen.
Naora : did you ask to the seller there? May be they found it and saved that book.
Julian : No, i didn't.
             OK, i am going to ask the seller.
Naora : OK, you should ask that book as soon as possible because i am afraid that they who find your , forget where they put it.
Julian: yeah, that's right.
             Thank you for your suggestion.
              I am going to canteen now,
              I am first.