There are few, if any, words that are the same across all languages and language families, but a team of linguistic researchers from the Max Planck Institute for Psycholinguistics in the Netherlands think they might have found one:
Wait, huh? Huh? Is “huh?” even a word? I’d always considered it more of a verbal tic, but the researchers argue that it is, and that it’s one of the only words that needs no translation. They listened to recordings of people speaking ten different languages from different language families around the world, and analyzed written texts from 21 more. They’ve concluded that “Huh?”(or a very similar sound) is used in all of these languages in the same way: as an attempt to clarify meaning when one person isn’t quite sure they heard what the other one was saying.
While they have not yet verified the existence of “huh?” in all of the world’s almost 7,000 languages, but head researcher Mark Dingemanse told Smithsonian.com, “We are ready to place bets.”
As for whether or not “huh” is a word, the researchers argue that it is:
“A true word is learned, and follows certain linguistic rules, depending on the language spoken. Huh? fits this definition: For one thing, huh has no counterpart in the animal kingdom; for another, unlike innate vocalizations, children don’t use it until they start speaking. Moreover, in Russian, which doesn’t have an “h” sound, huh? sounds more like ah? In languages using a falling intonation for questions, like Icelandic, huh? also falls. All in all, Dingemanse concludes that huh? is a bona fide word with a specific purpose “crucial to our everyday language.”