Grammar is another one of those courses that students usually hate. It can be tedious, and it is definitely not something that involves concrete thinking. This subject is almost totally abstract thinking. Using visuals and possibly manipulating words with cut out cards can bring a concrete/visual aspect to the learning of grammar,but it is typically one of those subjects that we gain a greater understanding of as our minds mature into abstract thinking.
I personally was a good student during elementary, middle, high school, and college. Yet, I find today as I teach grammar I see the logic in it much more easily than I did then. It is true that as our minds mature logic and abstract thinking come more easily. As we teach seventh grade grammar, try to make it as concrete as possible. I enjoy using an online homeschool curriculum with my children, do to the fact that it gives interaction with the concept as well as fun drill and practice for the student.