Mother, bark and spit are among 23 oldest known words that researchers believe date back 15,000 years.
The words, which are revealed in a new PNAS paper, all come from seven language families of Europe and Asia and researcher think that they were part of a linguistic super-family that evolved from a common ancestral language, the Discovery News reported.
These words 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.
At the beginning of the study, Mark Pagel of the University of Reading's School of Biological Sciences and his colleagues looked at 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 in the PNAS paper.
Researchers had assumed that most words couldn't survive for more than 9,000 years. The timeless nature of the 23 words instead reveals their importance to us over millennia.