Many of those powers were about surpassing human difference, so I would guess towards more of that:
But—don't you want the language you speak to your friends to be the same as the language you use to organize your own thoughts? How can you accept a wall between the world you see, and the world you're allowed to talk about? Doesn't your soul die a little bit?
I am not quite sure such unity of language is possible.
My thoughts really aren't organized in words. (I hope to eventually write some posts about it, but:) My general understanding is that I have some underscrutinized mental activity that hosts a whole lot of models, prediction engines, and such; and that additionally there are many speech-generators that can take these wordless representations and convert them into words, sentences, texts of various languages. (into an echo in a verbal loop; into a sequence of muscle contractions that hit keyboard buttons; into a sequence of muscle contractions that produce sounds of speech.)
I can readily name a dozen distinct generators, and assume there are more. They adjust for a lot of social context — politeness, friendship, feelings of acceptability of topics. Whether I'm lecturing or questioning or bantering; who I am talking to and what words they will find persuasive. Whether I'm having fun or trying to explain or trying to formalize concepts or trying to express feelings. Heck, I speak 2.03 languages; empirically their generators borrow a lot from each other, but otherwise they're as different as it goes.
When I'm writing notes, I again have many modes of speech-generation. There's the babble mode; there's the mode of writing a coherent post that adresses something; there's a mode of taking extremely verbose what-is-happening notes; there's a mode of trying to write a zettelkasten note. These modes turn on different heuristics for {what should I do next}; they produce different results, leave different mental impressions.
These langauge generators are optimized-ish for different purposes, of course, and----I wouldn't have it any other way? Optimal ways to express my thoughts in private, to talk with my friends, and to give speeches are different, for reason that — I am tempted to argue — is implacable: these situations' have significantly different spaces-of-consequences for same sequences-of-words; of course I would learn to optimize them separately, and therefore use somewhat different languages for them.
Likewise, writing modes are useful for decidedly different outcomes: I won't get a good public-facing text by babbling; formal public post format is way too slow and stifling to represent an ongoing conversation with maximal fidelity; such representations are not optimized for later skimming; a (permanent) zettel note cannot help me catch subtle in-the-moment intuitions and produce insight.
(On that perspective, I would in fact think of English not as a single language, but more of as a generic protocol that allows an amount of distinct ?speech modes? to be implemented on top of it.)
(Disclosure: I have never seriously considered whether maintaining these multitudes is a price I might not want to pay. It definitely feels like the cost of keeping track of context and hosting multiple language modules is totally worth being able to optimize for so many things in separation, but I might be lost in the haze of the argument.)
So my answer here would be:
The link moved; here is the current location of the lecture in question and here is the course page.