Excellent. Our first two-syllable word. I have to scroll back and forth a bit in the waveform data to get the chords right. The first syllable has just two notes and the second has five! Rocky can make at least five different notes at the same time. He must have multiple sets of vocal cords or something. Well, he has five arms and five hands. So why not five sets of vocal cords?

I don’t see a mouth anywhere. The notes are just coming from somewhere inside him. When I first heard him speak, I thought it sounded like whale song. That may have been more accurate than I thought. Whales sound like they do because they move air back and forth across their vocal cords without expelling it. Rocky may be doing the same thing.

Tap-tap-tap-tap!

“What?” I look back at him.

He points to the “λ” symbol still in my hand and then to me. Then back to the “λ” and back to me. He’s almost frantic about it.

“Oh, sorry,” I say. I hold the digit up properly and say, “Three.”

He does jazz hands. I throw some jazz hands back.

Huh. While we’re on the subject…

I stand still for a moment so he’ll know there was a break in the conversation. Then I do jazz hands and say, “Yes.”

I repeat the gesture. “Yes.”

He does it back to me and says, “♫♩.”

I note and record the frequencies in my laptop.

“Okay, we have ‘yes’ in our vocabulary now,” I say.

Tap-tap-tap.

I look over. Once he knows he has my attention, he does jazz hands again and says, “♫♩.” Same chord as before.

“Yes,” I say. “We covered this.”

He holds up a finger for a moment. Then he balls two of his fists and taps them together. “♪♪.”

…What?

“Ohhh,” I say. I’m a teacher. What would I teach someone who just learned the word ‘yes’?

“That’s ‘no.’ ”

At least I hope so.

I ball my fists and tap them together. “No.”

“♫♩,” he says. I check the laptop. He just said yes.

Wait. Does that mean it’s not no? Is that another yes? Now I’m confused.

“No?” I ask

“No,” he says in Eridian.

“So, ‘yes’?”

“No, yes.”

“Yes?”

“No. No.”

“Yes, yes?”

“No!” He balls a fist at me, clearly frustrated.

Enough of this interspecies Abbott and Costello routine. I hold up a finger.

He unballs his fist and returns the gesture.

I enter the frequencies for what I think is “no” into my spreadsheet. If I’m wrong, I’m wrong and we’ll work it out later.

I hold up the “+” symbol. “Four.”

He holds up three fingers on one hand, and one finger on another. “♩♩.”

I make note of the frequencies.

For the next several hours, we expand our shared vocabulary to several thousand words. Language is kind of an exponential system. The more words you know, the easier it is to describe new ones.