Two purposes are entertain and persuade. Entertain can be in a fictional story and persuade can be in a advertisement that attemps to change the readers opinion or encourage them of something. Hope that was what you were asking for.
"I am behind on my work.you are,,too'.You should come over and we can study together
Explanation:
it is because Nick realised that he really has to do is school work on time instead of going out
J.K. Rowling is the author of Harry Potter
(that's what she is known for)
hope this helps