"Can you type?"

"I don't know what that is."

"Okay.  I will try to be back in not very many minutes, and then we're going to need to communicate mostly by text for a while.  Does that sound okay?"

"Yes."

Nod.

He goes and helps his parents unload the groceries, and he thinks succeeds at acting mostly casual.  His mom nags him about whether he's done his homework, and normally he would lie and say it's done but actually the excuse to hang out undisturbed in his room for a while is very welcome, here.

So he's back after not too long, with beef jerky in hand to wordlessly offer Promise.

She looks at it quizzically. Opens her mouth, though she looks confused about it.

He tears off a small enough piece that it should be chewable on its own and feeds it to her.

She chews once and then spits it into her hand.

Here is the trash can; she can put it in that.

He takes the laptop back.  This is typing, he types.  If you learn how, we can send messages even when we're not in the same room.

She stares at the screen and the keys and back in total bewilderment.

He makes a show of hunting and pecking, Like this.

Can I watch you write?

Nod.

I write like this. I don't know what those things on the little squares are.

Could you please do that some more?

I did not like that most recent food but I suspect you noticed.

I did notice that.  Do you know what video is?

Headshake.

You saw that there were pictures in the Wikipedia articles, which are like drawings but easier and more accurate.  Video is what happens if you take enough of those, and fast enough, that they seem to move.  And it captures sound, too.  So then there exists a record of a period of time.

I would like to film a video of you writing, because I don't understand how you're doing it.

...with... my hands? Sure. Go ahead.

He points his phone at the paper and gives Promise a thumbs up.

I don't have any specific thing I want to write but here is some text anyway. How long of a passage do you have in mind?

He stops recording and gives her another thumbs up.  ...Watching it back does not really illuminate things.

There are additional papers and writing utensils on his desk; he doesn't have to commandeer hers to put down, That was enough.  When I write it looks like this.  He's left-handed and the symbols he writes correspond exactly with the motions he makes, are the major differences.