1) The words that Simon said to Ralph that made them both smile were: "I just think you'll get back alright." These words encourage Ralph as if they give him a hope of rescue. He became hopeless and thought that his rescue would never happen until he heard what Simon said. Simon said 'you will' instead of 'I will' and this tells us that he himself does not believe in rescue but anyway tries to make Ralph happy somehow.
2) The choice of words is very significant in context of the story because Sam foreshadows that some of the other boys might not make it off the island, pointing out that someone will never get home. He believes that Ralph is capable of surviving due to his strength, but he also thinks that other boys have no chance as they are too weak.
