Imagine this: you've built a time machine, so you can travel back 15,000 years to find out what the hunter-gatherers were up to.
But how are you going to communicate? Your new friends certainly won't understand what you're saying, right?
Well, according to a new study from the University of Reading in England, there might be some words you can say to each other.
The researchers believe that languages spoken today across Europe and Asia, actually come from an ancient language at the end of the last ice age.
That ancient language, they believe, evolved into seven more languages that formed a "superfamily", which then split off into separate languages over the next 5,000 years.
The researchers identified about two dozen "ultraconserved words" they believe were in use 15,000 years ago, and are still in use to this day.
Here's a phrase the researchers believe might be at least partly understood by those hunter gatherers:
"You, hear me! Give this fire to that old man. Pull the black worm off the bark and give it to the mother. And no spitting in the ashes!"
All the nouns, verbs, adjectives and adverbs in those sentences have survived, without many changes, according to the researchers.
Most linguists believe that words can't survive more than 8,000 to 9,000 years because many of them evolve too rapidly and end up being replaced by words from other languages, so there's no way to preserve them.
But the researchers behind this study believe there was a single Eurasiatic language, that is the common ancestor to about 700 languages today, spoken by more than half of the world's people.
A graphic showing the similar-sounding "proto-words" the researchers developed (Image: The Washington Post)
As for what the original language is, and how it sounded, that's still something of a mystery.
"We've never heard this language, and it's not written down anywhere," said Mark Pagel, the head of the study, told the Washington Post. "But this ancestral language was spoken and heard. People sitting around campfires used it to talk to each other."
Here's how the team reached its conclusions: they studied "cognates," which are words that have the same meaning and a similar sound in different languages - for example, "night" (English), "nuit" (French), "noch" (Russian), "nat" (Danish), "nos" (Welsh), and "noapte" (Romanian) are cognates.
But those examples are from a single language family - the Indo-European. The researchers looked at seven different families in their search for cognates.
When they found similar-sounding words in different languages, they created what they imagined would be the cognate's ancestral word, using their knowledge of how sounds change between languages.
Those made-up words are called "proto-words," and it's those words that the team compared between languages: for instnace, does the proto-word for "hand" sound similar in the Dravidian (languages of South India) language family and the Indo-European one?
They found many similarities, particularly with words that would be used most often.
From there, they compiled a list of 23 words they call "ultraconserved." Some are not really surprising, like "I", "we", "man", "mother", "hear," and "give".
But others, like "to spit" and "bark," were unexpected.
"I have spoken to some anthropologists about that, and they say that bark played a very significant role in the lives of forest-dwelling hunter-gatherers," Pagel told the Post.
And as for "spit," the theory is that it sounds so much like the action it describes, no one could improve on it, so it survived.
Here's the list of alI 23 words the researchers identified: I, That, We, Who, This, What, Ye, Old, To hear, Hand, Fire, To pull, To flow, Ashes, To spit, Worm, Thou, Not, To give, Man, Mother, Bark and Black.
The study is published in the journal 'Proceedings of the National Academy of Sciences.'