What Are the Oldest Words in English?
By Bess Lovejoy, the mag

We don't know for sure, but there are contenders. In 2013, researchers at the University of Reading in England looked at a variety of words that sound similar across different Indo-European languages. By analyzing the rate of change, they arrived at 23 “ultra-conserved” words that have likely sounded the same for the last 15,000 years. The oldest? I, who, two, three, and five. Other ultra-conserved words include man, mother, ashes, and worm.