At the beginning Salva was in school and his village was being attacked, during this moment Salva was being very cooperative, I know he was being cooperative because he wanted to run back to his village and find his family but he didn't instead he listened to his teacher.
In the middles of the book,Salva was so brave. he was brave because he crossed a river full of crocodiles after he saw someone get eat'n. He was still brave enough to cross it.
At the end of the book Salva was on his way from America to see his dad who he thought was dead. At this point Salva was very hopeful that he would actually find his family and he did.