Language
Harry was used to boredom and so for the first few days of his trip, he didn’t talk. He watched the scenery go by, watched as the Forbidden Forest became mountains became grasslands became farmlands. He listened as the Threstral’s hooves clomped upon leaves and grass. He had practice sleeping sitting up from primary school, and dreamed of being back at Ms. Figg’s, listening to her cats hiss at one another.
Hissing became something Harry did to keep himself occupied. Eventually he began hissing to himself. “Sssstupid Snape stealing my wand and stupid Madam Pince taking me to the Hospital Wing and stupid Pomfrey feeding me truth potion sssstupid stupid stupid.”
”Sssstop dwelling on sssstupid foolish humans, you foal. You’ve left for greener grasses, and you’re gonna find a better place than that overcrowded sssschool.”
“Who- who’s there?” Harry asked, although he could feel the vibrating throat of the Threstral. They couldn’t talk, could they?
”Tis I, your Thestral. You ride on me for days without conversation, and I’ve grown bored. We’re social being, thestrals are.”
”You can talk? Why didn’t Hagrid tell me you could talk? How did you learn English, anyway?”
”‘Tis not English, youngling, but Parseltongue. Sounds of the ssssnakes and snakelings. We thestrals come from the crossing of a dragon herd and a centaur herd, hundreds of years ago, that bred and became a new speciessss. Dragons have Parselmagic and centaurs have language, so the magic gifted to our species at birth enabled us to speak the tongue of Parsel as well.”
”Oh. How do centaurs know language?”
”They learn when young the tongue of the land they live. French centaurs parle Francois, Spanish centaurs speak Spanish, the centaurs in the new world speak the forgotten languages of the tribes they reside on the land of. Language is a messy magic - I’m not sure why we can understand each other but you cannot communicate with dragons.”
”I don’t know either. I don’t know anything. Where are we?”
”I don’t know the human names for this land. I will get you to your Diagon Alley, fear not. I’m following the wind currents to navigate.”
”Cool.”
And with that, Harry had little trouble braving the frosty autumn traveling with his new friend. He liked having friends, and learning all the Thestral knew from centuries on Hogwarts land. As for the Thestral, they too liked conversing with the human and having the opportunity to spread their wings or run out on their hooves as they wished, with no parents in the herd to stop their antics.