"My room." This has been enough not lying down for now.

Nod nod. They can go back to his room; the spare handcomp is on his bedside table, as is one of those bracelets, not currently lit up. The nurse shows him how to set up a password and access the internet and also the hospital's menu website. 

"These are very important here?"

"The handcomps are very important, yes, you can use them to get information about anything or read books or send and receive messages or take notes or get directions to a place or take pictures or manage your schedule or do math or listen to music. The bracelets are how we indicate interruptibility; I've been assuming you lost your equivalent or didn't have it on you because you were at work but if you've actually been signalling with some other thing I apologize."

"...everything I would have been interrupted from is in the future."

Perplexedness! "Well, yes, but what if you can't get home today? Or just don't want to be interrupted while writing down all your cool future knowledge?"

"I... don't think you will be able to get me home."

"If you can't get home then you have my sympathy and I will help you get acclimated here," says the nurse solemnly.

"Thank you, I appreciate that."

"I have to go help my other patients for a bit, but you can get some food delivered and I'll be back in less than an hour unless something unexpected happens."

The hospital menu has a lot of different kinds of fruits and nuts and vegetables, and bread with miscellaneous spreads on it, and cheese, and tofu, and several flavors and nutrient ratios of packaged meal bar. There's pictures of everything, and if he wants to teach his handcomp his alphabet first there's also nutrient information and patient reviews available for all of it.

He will order based on pictures - some bread, some tofu, some cabbage - and then teach it the alphabet.

Not long after he's done with the alphabet the food shows up. There's a little packet of butter with the bread and little cups of a bunch of different sauces for the cabbage dish and the tofu dish, both of which were roasted with hard-to-identify foreign spices. 

Huh, weird that it didn't just have a default sauce if it's going to have a sauce at all. He tastes them and winds up putting kind of a lot of sauce on and mopping it all up with buttered bread.

Fortunately the hospital plans for people who are having new-to-them manual dexterity problems and provided plenty of napkins and some kind of moist towel in a packet thing, so if this process gives him sticky fingers it will not be for long enough to impede him in using his new handcomp.

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."