If you want info on how to study for English, alot of info about it has already been provided in the post: Format of the AKU test and Time Management!
If you really want to prepare something, i would suggest going through a few SAT critical reading and sentence structure questions for practice. But don't waste your time on this as you can never really predict what questions will come in the test. As for the argumentative essay, please pay attention in your General Paper classes in Alevels. If you don't take GP, try having a little interest with newspapers (preferably the international and letters to the editor sections) to broaden your scope of knowledge. I'm saying this because the argumentative essay we encountered in 2012 was something about whether or not