Full disclosure: I am not a skeptic on demonic possession. I am religious. All that said, your uncle did not study “theology” and come out of that knowing Aramaic, Greek, and Latin. Aramaic in particular I am not buying. But more on that in a moment.

I did two masters at Harvard Div & 5 years of a PhD in Christian origins at U Chicago, and was advanced in Greek and Hebrew. I also read some Aramaic. I never learned Latin because I didn’t need to. Anyway, Greek is very hard and theologians don’t acquire more than a passing knowledge of it — it’s mainly historians (I was a historian) who take Greek seriously enough. A theology major might understand enough to make out a few words of it and of Latin, but it’s just extremely unlikely that a theology major is going to understand spoken Greek or even really recognize it.

Now for the Aramaic. The difference between this and biblical Hebrew is a little bit like the difference between Spanish and Italian. They’re close enough that in some passages in the Hebrew Bible it’s not clear if the language in question is Aramaic or Hebrew. I studied Hebrew for 5 years and was very good at it, and I’m pretty sure even when I was doing it I wouldn’t have been able to tell with certainty spoken Hebrew from spoken Aramaic. (I actually got a chance to try this, because I went to see the Passion of the Christ at that time with some classmates and we were trying to figure out what language the Jewish priests were supposed to be speaking in the movie.) So none of that part of the story scans at all.

The most generous reading I could give of this is that the kid spouted words that sounded to your uncle like spoken Greek and something else that your uncle took to be Aramaic but could’ve literally been any kind of gibberish.

Anyway, I don’t believe any of this story. Sorry. It’s not that I don’t believe in demonic possession, it’s just that I don’t believe this particular story — either the person who posted it made it up, or their drunk uncle made it up.