Then he will teach it more words.

It will happily accept words! And also let him configure the onboard clock in his time system and calendar, if he wants to do that.

About fifty minutes after the nurse left, he comes back with a person of uncertain gender with tattoos of little birds all over both forearms. They introduce themself as Alenn. "I'm a linguist; can I ask you some questions about your language?"

"Yes, that's fine."

"Some questions" apparently means "on the order of a hundred questions in batches of five".  First they want to copy the latest translation package off his handcomp and then they want to know how his language originated and how many mutually unintelligible languages he's aware of and whether this batch of sentences are grammatical and how to translate these phrases and how Ibyabekan does uncertainty-level-and-type-markers and sarcasm-markers and facetiousness-markers and what words Kyeo would coin for various imaginary concepts and how similar are the connotations of this pair of synonyms and if Kyeo doesn't redirect them they'll go off on a ten-minute tangent of asking about the Ibyabekan calendar system.

Ibyabekan is descended from Old Sohaibekan and Kyeo doesn't actually know what the previous language was. They say Ibyabekan and Outer Sohaibekan are still mutually intelligible. He can list other languages spoken - and he knows a decent amount of Kularan, though he'd be tripped up by anything too informal or requiring very specialist vocabulary. Most of those sentences are grammatical - he doesn't know the source language but this translation seems most felicitous - Ibyabekan doesn't verbally mark uncertainty nearly that much - he will pull coinages out of compounds for them - pretty close but differing mostly in register - yes he can explain the Ibyabekan calendar to them.

All of these answers spawn more questions! Alenn is updating the translation package as they go; the translation of their questions into Ibyabekan gets slightly less stilted and also they start asking some of the questions in (oddly accented) Ibyabekan.  At some point Alenn interrupts themself to tell the nurse, "He's much more likely than not from the future! Or possibly a low-budget alien; neither of the languages he knows are plausibly within a hundred years of us without an entire new language-construction project and they don't smell constructed either. If I was you I'd get that physicist and possibly also a historian and you can quote me on that."

"I thought it was already determined I was from the future."

"Kars thought you might be pretending or have a lot of fake memories or something. Time travel is completely unheard of, right, physicists thought it was probably impossible, whereas people lying or having fake memories is something that happens occasionally, but I can tell your language wasn't made up by one person and nobody has fake memories of an entire language, so something unheard of has happened and it's probably the one you said it was. Do you know how to make any cool future technology? Even just knowing what's possible is great; what's your top five inventions of the last hundred years?"

"Well, there's the faster than light travel - I'm not actually sure of the date on that - I'm not a historian."

"Faster than light travel is very cool; the physicists will squeak like kids at harvestfeast. Does it traverse the intervening space or is it point-to-point jumps or site-to-site with infrastructure or other?"

"I've not personally been on a ship like that, I was deployed in-system, but I believe it's point to point, only many points do not work and so most trips require multiple legs."

"Ooooh, does that mean it's more practical to model space like a graph structure instead of like coordinates in three dimensions? Is the fastest route to a place ever one that involves a step where you get farther from your destination? Are the points that work correlated with where stars or planets are at all?"

"I think all of those are yeses."

"Wow, your cartography must be amazing! What do your star maps usually look like?"

"...they would be hard to draw, but they have a lot of colorful lines on them and are rendered in three dimensions."

"Nice! Ooh, I am going to make a fortune in the prediction markets--"

"Can you hold off on that? I think Kyeo should get dibs, it's not fair if we get all the profit just because he's been injured and isn't used to our tech yet."

"Point taken. Kyeo, you should go make a fortune in the prediction markets! I can show you the app if you want."

"Ah, you use money. That makes sense."

"Ooh, do you not? What do you use instead? Also we should get you set up with a bank account so you can receive negatax payments and get an apartment and have seed capital et cetera."

"I don't know what most of those things are because on Ibyabek everything we need is freely available and people do their jobs without resort to bribery."

Kars asks, "But how do you know what job is the most valuable if you don't get paid?"

Alenn chimes in "Maybe they automated all the unfun-but-important jobs?"

"People can tell what jobs are necessary without being paid, and do them whether they're fun or not."

"Facetiously, are you sure you aren't a low-budget alien? Seriously, we should get an economist in here. And get you that bank account, because we can't coordinate on the right number of people doing every job nearly that well so we bribe the people doing the underpopulated ones until it balances out," says Alenn.

"Also money is a cool way of keeping score, but I guess if you can tell how much value you're creating without that you wouldn't need it for that either. I'll go get the hospital social worker, he'll know more about how to get you set up with everything and into all the databases," says Kars, and leaves.

"...thank you," says Kyeo as he goes.

"I'm not an economist and won't have as good of questions as they will; do you want to ask me questions about the present for a while?"

"...how does money work."