Frederic Henry's perspective and attitude about war changes drastically in this story by Hemingway. How and why does Henry's change happen?
Do you really want us strangers write your essay for you? I would suggest against it as many of us would write something completely wrong or you could get an answer from someone completely clueless and you would have no idea how bad it would be.
In addition you would not learn - which is the actual purpose of school.