Mother, bark and spit are just three of 23 words that researchers believe date back 15,000 years, making them the oldest known words.

The words, highlighted in a new PNAS paper, all come from seven language families of Europe and Asia. It’s believed that they were part of a linguistic super-family that evolved from a common ancestral language.

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What this means is that if an Ice Age person from 15,000 years ago could hear you speak today, he or she could probably understand you, so long as you used these handful of words.

Here they are:

thou, I, not, that, we, to give, who, this, what, man/male, ye, old, mother, to hear, hand, fire, to pull, black, to flow, bark, ashes, to spit, worm

You can tell that fire was a big deal back in the day. “Worm” comes as a surprise.

Mark Pagel of the University of Reading’s School of Biological Sciences led the research. He and his colleagues began with 200 words that linguists agree are common among all European and Asian languages. They then determined which sounded similar and had comparable meanings across the different languages.

Next, Pagel and his team determined the roots of those words, resulting in the list of 23.

“Our results suggest a remarkable fidelity in the transmission of some words and give theoretical justification to the search for features of language that might be preserved across wide spans of time and geography,” Pagel and his team wrote.

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Previously, researchers suspected that most words couldn’t survive for more than 9,000 years. The estimated shelf life is due to replacement words and turnover in languages themselves, since entire languages can go extinct over time.

The timeless nature of the 23 words instead reveals their importance to us over millennia. Things like technology may forever change, leading to new words in our vocabulary. But fire ashes, spitting, old mothers, worms and more clearly are constants for us.

Check out this very cool page that lets you hear how some of the common words sound in various ancient languages. If you only have time to click on one, listen to how “to spit” is said in Kartvellan.

Image: Depiction of a Cro-Magnon hunting party slaying a woolly mammoth. Peet Simard/Corbis