It steals from everything. It stole from other Earth languages, and now it steals from other galactic languages. Here are some words it stole from Vulcan to talk about Vulcan-related things.

This delights him. Quenya stole from Pax, a little, but they spent a lot of time refining the borrowed words to be beautiful by Quendi standards.

English makes things pronounceable, and often abbreviates or diminuates from there, but is not optimized for beauty; it's much too decentralized and people's tastes vary too much.

...the Quendi definitely optimize their language for beauty, otherwise talking wouldn't be a source of joy and delight.

Well, English has pretty words and people make pretty sentences of them, but it actually has several words that are widely considered unpleasant to hear, like 'moist'. People complain about it but no one has the ability to decide by fiat that it's not what people say anymore. If someone tried to replace 'moist', it would just wind up with different use cases and connotations, like 'damp', and then there would be another word but the one people don't like would still be there because it would sometimes be the most precise word for something being described by someone who didn't avoid saying it.

If he thought a word was ugly they could debate it in the forums and if enough people agreed then it'd be changed officially and everyone would stop using it.

There are Earth languages that police or used to police what words could officially belong to them. English proved more adaptable even though it's got awful grammar and irregular spelling and a gigantic vocabulary and sounds some people can't pronounce: it is annoying to learn but once you have learned it it will do its level best to be the most useful language for any situation.

"I don't think it's ugly. I don't think I've ever heard a language and thought it was ugly. But some are so beautiful they're a joy to speak."

"I wonder what you'd think of Klingon. I only know how to say a couple sentences in it though."

He looks at her expectantly.

She snorts, and says-and-translates that this is the Federation survey vessel Prometheus etc. in mediocre Klingon.

"I have to learn so many languages."

"There's lots! Most people get by with one or two."

"But aren't they just sad, all the time, that there are all the other ones they don't know?"

"Not so much. I only speak English and Vulcan and translations of that utterance in Klingon in a few more languages and that's it."

"Bella do you think we can invent something like the necklace that makes us go even faster?"

"I'm not sure it would be a good idea..."

"Why not?"

"When we came up with the necklace it was shielding us against an effect that Valinor was having; this would be different, trying to accelerate us as an effect of its own. Also at some point you'd run into problems where you couldn't move fast enough to keep up with your brain if you wanted to do anything other than sit and think, so it seems like a good idea to focus on ways to be more efficient that don't have that problem first and then resort to that later if we really need it. T'Mir, ballpark how many languages are there in the galaxy here?"

"Um - with living speaking populations - counting uncontacted planets - certainly billions, possibly tens or hundreds of billions."

"...and I think you'd run into a problem if you decided you had to learn them all this week and the best way to do it was going faster. You might be able to invent a magic thing that helps with languages in particular? There's translation magic in Materia, you could try to come up with a kind that teaches instead of just translating."

"I guess I can't learn all the languages before we fix everything else on this plane, then."

"Yep. And as long as you can't learn them all in anything resembling a timely manner however fast you go it seems more efficient to find a way to deal with not knowing them than to just try to go really really fast."

"Like doing other interesting things. I can tolerate not doing all the interesting things if I'm doing some of them and they're really interesting and this is."

"Sure."