Systemic Functional Grammar is a nicely coherent approach to linguistics which has occupied much of my summer. I'm going to be trialling it as an way of helping to structure the course this year.
This page, from an Australian website, has lots of materials to help you get a grip on SFL. Try the introductory booklet – most of the terms and ideas there will be familiar to A2s, but with some new ways of looking at things, and fitted into an overarching framework that might help make things click.
http://www.mourass.eq.edu.au/functional_grammar.htm
