Forrest watched intently again not to make any mistakes. He had to admit that he was learning things every day and it was good, but it'd be a liiiiiittle bit better too if he learnt spells other than just cleaning. So far, only transfiguration wasn't focused on cleaning--and even then, they would prepare some parade to gain money.

Eh. What else could he do but follow the directions?

Wand out, he closed his eyes momentarily and revised what professor had just shown them. 'Vitrumonia,' his lips read out without any sound, 'vee-truh-moh-nee-uh! Vitrumonia!' He had yet to explode anywhere even though he had never practised spells before trying them with wands--when he failed in a spell, nothing ever happened, usually--but he practised this one without his wand nevertheless, because something inside him told him that this professor would explode him if he broke something. So, dropping his wand on the table, he whispered the spell and drew a line in the air.

"Vitrumonia!" A small line. There.