Well, it might be different with other people, but for me, the way I RP is a part of my personality. Iunno, it may just be me, but its not something you can easily change. If the way Hawk RPs is a fundemental part of his personality like it is with me, well, its not something you can teach him in the same sense, plain and simple. I mean, sure, it would be easier if he could just learn it as if he were at a school. But thats just not it. Im good at putting on different personas; when I RP, I put myself in my character's place and try to act with the personality of my character(if you dont know, Persona means mask, but usually refers to the 'masks' we use to hide our true feelings, like a bully who's hiding his soft side). However, this just comes naturally to me, and explains why my posts tend to center around a single character; Im not good at wearing multiple personas. I'd end up posting Hiro's thoughts all over the post, with maybe Sara saying something, as a example pertaining to this board.
However, this might not be as easy for Hawk, putting on different personas. Perhaps his personality cant conform to that of his characters, or he just cant put himself into their heads. Thats just not something you can teach, ya know?