I went to sleep last night with gen fic in my head and woke up with slash. At some point, this has simply got to stop. Anyway, you're getting the gen fic, because it's much shorter -- a double-drabble, as it turns out -- and because it's less disturbing. Sadly, it's also much less hot and probably a lot less interesting, but at least I wrote something that's not a random snippet of dialog from a story that's never going to happen.
So, one tiny ficlet on the subject of the Doctor and language:
Title: Paleolinguistics
Fandom: Doctor Who
Length: 200 words
Rating/warnings: G-rated. Spoilers for "The Sound of Drums."
Paleolinguistics
The TARDIS makes it unnecessary to learn new languages; it doesn't make it impossible. At least, not if you understand how it works. And if you have a Time Lord brain it's a simple perceptual trick to hear the sounds as they're uttered and the translation simultaneously in your mind.
The Doctor speaks English fluently, and has for a very long time. He uses it more than he uses his own language; it helps him avoid expressing too many concepts that won't translate for most of the people he knows. He even thinks in it, surprisingly often. He likes its fluidity, the ease with which it lends itself to wit and wordplay, even if it lacks the precision of his native tongue.
When he takes up the phone to speak to the Master, he does so, unthinkingly, in English. He's expecting the conversation to be difficult, but he's not at all prepared for what the sound of the Master's reply, uttered in Gallifreyan, does to his hearts. Though perhaps he should have anticipated it. A language with one speaker is a dead tongue. A language with two is alive.
He doesn't go back to English for a very long time.