"You need a wand, and a spell to stop. I'm not going to teach you anything else until I know you can cast a counterspell." He thought about which spell to use, and aimed his wand at his desk. "Accio bowl!" A bowl floated obediently over, and he rolled his eyes impatiently as it floated over. "Did I mention magic requires you to be specific?" He set the bowl down and summoned over the other, empty bowl.