Essay evaluation

After looking over my essays several patterns have become evident. For the most part evidence isn't a problem which means that I know the material. How prefer global context for both forms of the essays is one of the things that gets me. Perhaps I don't understand what I'm supposed to do or I'm just having trouble thinking of things other than what the essay is on. I've never been able to get expanded core because I usually miss one of the basic core which doesn't allow me to get expanded core.