The writing system is obviously also entirely new to him, so when she changes that setting he aks for something to write with so he can compare it to the one he’s familiar with. 
After a longer while of language practice, Kellen is a bit tired and would prefer asking questions about this world, although he’s not saying it out loud yet.

Cynthia notices Kellen being tired well enough that she gives him a break from the language practice. She asks him if the place he's from is like the place he is now.

Kellen shakes his  head. 
“No, lots is different”, he pauses for a moment, figuring out how to say things, “you have no magic”, he uses his own language for the last word.

Cynthia is confused. She scrolls through the phone, hoping that she eventually manages to show Kellen the pictogram for the new word she's never heard before. Magic is symbolized by a bone in the middle of some stars, but she more or less flies past it as she tries showing Kellen many different pictograms hoping to get lucky.

Between his idea of magic being very different from the image and him not being sure that there even is a word for it in her language, he doesn’t notice it. Instead, after being shown many pictograms unsuccessfully, he decides to try to demonstrate. He won’t do anything very big since he isn’t sure if he’ll be able to refill his reserves but he can still try to get the idea across.
 

He takes a deep breath, feeling the magic-less air and connecting his own magic to it. Kellen then extends a hand towards Cynthia, palm up. His eyes glowing slightly, the air above his hand swirls, forming a small whirlwind.

Cynthia jumps back and shakes her hands, shouting "Magic! Magic" and rushing to tap the pictogram of the bone in a frenzy. "Real magic!"

He lets go of the magic, his eyes dimming back to  normal. Kellen waits for Cynthia to calm down a bit. He feels a bit emptier and hopes that the theories about living beings producing their own magic are true. 

"And other people also do magic?" Cynthia asks. "What magic is there?"

“Yes. All people”, he nods. Then he checks with the pictographs to make sure he’ll use the right words, “Four magics. Air,”-he gestures at himself-“ water, fire and stone. Uhm… shadow? Not sure. Maybe it’s… story?” What he’d like to communicate is that there are rumours of some other types but he doesn’t know if they’re true. 

Cynthia nods slowly, twice. She's... not sure what to about any of this. Kellen's magic is real, but she doubts anyone else's is. So... he's unique, and Cynthia doesn't think he can really use his powers for much...

For the better or for the worst, that last part is true. Kellen’s afinity for magic is pretty average back at home and that’s without the possible dangers of no ambient magic. On the positive side, that should make it easier for him to fit into this world. 

After an awkward pause in the conversation, Kellen clears his throat, “Earlier… what was that brought the food?”

"It's a" she decides to take her phone out of Kellen's hand, for now. "Robot"! the phone says. "Someone I grew up with knows a lot, lot more about them than me. I just know they come here with food and other things, and that they do almost all the things in factories, and some of the things in hospitals. I see a lot of robots in the hospitals, actually."

Kellen carefully repeats the word before continuing to ask questions. “Are they people? Animals? They look metal-like”

"No, they're only" this time finding the pictogram on her phone takes longer "machines!"

“Machines? Like that?”, he gestures at the phone, a bit confused. Are ‘robots’ like the golems and automata of myth, just not magical? 
“And do they-”, he pauses to check the word, since it’s more abstract it was one of the hard to understand ones, “think?”

Cynthia shakes her head. "No more than a clock or car thinks!"

Alright, he knows what clocks and cars are like but robots still feel different. Maybe he’s understanding things wrong but they seem more independent. And now that he’s thinking about it… what do they power  machines with here?

” What moves them?”, that’s vague question but Kellen doesn’t know tech-specific vocabulary yet so hopefully that’ll get his point across!

"Electricity!" This time, Cynthia doesn't feel the need to have the phone saying it.

Have they gone over that word yet? Because Kellen clearly didn’t understand it right if they have. 

She finds the pictogram of a lighting bolt on her phone. (Did she forget that she hadn't taught him that yet? Drat)

That… doesn’t clear things up for him. He thinks that she’d shown him the word already but Kellen doesn’t understand how ‘electricity’ differs from lightning and makes machines work. 

“Like in storms?”

"Like in..." Cynthia would say "like in this phone", but that's confusing, and storms have so much else going on that he might be confused and think electricity refers to something else in the storm! Aah. She tries anyway. "Like from a" this time the phone says it "battery! And phone" Cynthia points at the phone.

He can understand the idea of a battery, it’s like his own magic reserves or the ones of machines in his world. But he doesn’t understand how it stores and uses maybe-not-lightning!