I realize that this will be really, really hard for you to do, eco, but I think you need to consider not helping him with these assignments. If he turned in his best guess at what it was supposed to be, it would put the teacher on notice a lot better that he was having a problem with grasping the instructions. Part of the reason they summarize your concerns the way you describe is that all of his turned-in work is probably fine, and they don't understand how much you had to do to get him to a place of being able to perform like that.
