"I don't think I understand how to cast one spell while saying another," Harry Potter said, in frustration. "I keep on getting confused - changing the spell, rather than casting another one."
Smugly, Snape smirked, and said, "Try saying one spell until you have it on instinct. Limit it to a time that you can control - say falling out of bed."
Harry just looked at Snape, as that hadn't even been something on his radar. At all. Blankly, he nodded.
"Once you have a spell that you simply say, and do not cast, casting a spell automatically will come with time, and practice." Snape's mouth quirked, drawing itself up into nearly a flat line. "Practice, practice, and yet more practice."
For the rest of his detention, Harry got to work - Snape sat nearby, reading and correcting homework assignments. It was surprisingly peaceful, though occasionally Snape would call out a correction. Those were, by and large, helpful, so...
Before Harry left, he caught himself wondering what Snape would like taught in the homework club next, but resolved not to pry. If Snape had any Special Requests, he'd have said so.
Coming back from detention, Harry barely waved at Hermione in the common room, instead racing upstairs to his dorm. Everyone was there, working on last-minute finishing touches. Harry let his own magic stretch out, wandlessly giving a bit of it to a few flowers that were starting to flag.
"All set for tommorrow?" Harry asked, fighting to hold back a grin. He'd missed times like this - Gryffindors just being Gryffindors.
[a/n: Okay, taking guesses on what Harry's up to? Tomorrow will be interesting. Leave a review.]