ANSWER
The most frequently used word on the planet, regardless of language, is "ok". The word "ok" is American in origin, but has spread to hundreds of languages. American soldiers in World War II found the word already in use everywhere, from Bedouins in the Sahara, to the Japanese in the Pacific. It was the fourth word spoken from the surface of the moon. (Today, "ok" is frequently seen in a variety of software, right next to the "cancel" button.)
WHO GOT IT RIGHT: Wayne Rockett, Yanitz Grinell, JP Weigt, Bob Milligan, Marc Quinlivan, Steve Shuba, and Lauren Kelso.