A quiz is the most fun way to find out. Make one in seconds, send the link, and let the bragging rights begin.
Under the heading Who knows the most? on the front page: making a quiz and sending its link to see who knows most. "Let the bragging rights begin" is playful: the fight for the honour of winning starts, so use the language's own idiom for it
Umukino w’ibibazo ni bwo buryo bunezereza cane bwo kubimenya. Wukore mu masegonda, urungike umurongo, maze uwuzi menshi yegukane ishema!
