"Even though the Muggles in the Middle Ages forgot everything, the wizarding world managed to keep all of its knowledge - owing most likely to the fact that there wasn't a prevelant religious attitude towards burning books."
Ron very carefully placed another card on top of the west wing of his card house.
"So that's why so many of our spells are in Latin - like the Muggle church and things, Latin was originally the language of the wizard elite in Western Europe."
Harry ate another chocolate frog, and held the card up to Ron, who shook his head. Harry put Chodwech IVth into the pile of cards to trade. They both had him, then.
"Though wizarding latin is ever so much more complex than regular old classical Latin," Hermione rambled. "The typical spells syntax is actually a combination of the first person present with a thematic vowel - an amalgam from the greek, one would imagine, most of the best Hellenistic wizards learned Greek after all. Anyway, it's actually a whole new aspect and mood for a verb - like the active but exherting control over the environment!"
Hermione's eyes sparkled as if she'd unlocked the mysteries of the universe. Harry stiffled a yawn.
"Just imagine it. Latin grammar, because it's ever so organized, worked the best for focusing - not like modern English at all, with its imprecise nature. Latin was structured enough to develop a whole dialect just for spell-casting! and it's the grammar that makes spells possible!"
Harry watched Ron tip his head one way, then the next, frowning in concentration. Harry didn't know any Latin, classical or wizarding or otherwise, but learning grammar and verb forms like Hermione had been sounded like nearly the dullest thing in the world. Binns would probably love teaching it.
"Of course, it's been centuries since classical Rome," hermione went on. "Even Hogwarts, which was founded when Latin was still a spoken language at least some places - even if it wasn't the primary language in Britain - is a thousand years old."
Ron carefully placed another few cards. Harry opened another Chocolate Frog - Bertha Matilda.
"And just like English today, we've adopted spells from all over. Like words such as, I don't know, fjord, we've taken spells in for over a thousand years and made them part of the typical repetoire of a British wizard. Not to mention that all the Latin spells were combined with the Celtic magic and language as well." Hermione frowned. "Perhaps that accounts for the various incantations based around different endings than the--"
"Hermione," Harry said.
He blanked, grateful only that she hadn't gone into another tirade that included the words "para-subjunctive" and "syntax".
Hermione stood up, huffy. "Well, fine. If you're not interested in what I find to be the most facinating magical theory ever - just picture it! We could build our own spells." Harry felt a tickle in his nose. "We could modify existing spells ourselves!" There it was again. "This is as importan a theory to magic as quantum physics is to the Muggle world!" He had to be allergic to theory, Harry surmised, nose twitching.
Hermione said, "It's amazing!" Harry sneezed, and Ron looked mournful as his house of cards exploded quite literally - he'd been using an Exploding Snap deck - in his face.