I am in Chapter 2 and I've gotten quite a few neat spells by this point. The spells sit at the bottom left of my screen and each one has a number (1-4). So, if I hit the number that corresponds with the spells, it becomes highlighted. However, nothing else happens after that. Is there something additional that I need to do in order to use the spell?
I'm playing on single player mode, switching between the two characters frequently to get a feel for both. During combat, I watch my partner use some pretty awesome spells but I can't seem to make the same thing happen when I'm playing.