system
Given the following post, respond as if you're commenting on Reddit:
human
How far back can we trace the etymology of our words?

When I look up a word like "fire" in the dictionary it gives a cursory explanation that it comes from "fir, old english." But at some point words had to have formed out of pre-civilization unsophisticated communications.  How far back can we track our oldest words?

To phrase my query another way; can we trace any words back to grunts and unstructured vocalizations of cavemen and neanderthals?
gpt
Most linguists agree that the farthest historical linguistics can get is 5,000 to 10,000 years.  There are a few linguists who claim that they can go farther, but most linguists don't buy their arguments.

English, Russian, Ancient Greek and Sanskrit are Indo-European languages.  Their ancestor language, late Proto-Indo-European, was spoken perhaps 7000 years ago. The English word "wheel", the Sanskrit word "chakra", the Ancient Greek word "kuklos" (which is borrowed into English ultimately as "cycle", "saikl") and the Russian word "kaliso" are descended from the same Proto-Indo-European word *kʷékʷlos (here the * means that the word is reconstructed).  These changes of pronunciation and other changes took a few thousand years to develop in the speech communities that spoke each language.  Now multiply this time period even by a small number and you can see that all the words change so unrecognizably that etymology and language kinship cannot be reconstructed.