Hakuna Matata. You may recognize this phrase. You may even find yourself humming the earworm-provoking song of the same title from Disney's the Lion King. "It means no worries" goes the lyric. But Disney fails to mention that "Hakuna matata" means "no worries" in Swahili. Swahili – known as Kiswahili in East Africa – has its roots in a small tribal Bantu language spoken along one strip of Africa's eastern coastline. But these days, it's spread across the African continent. Today its spoken by more than 100 million people. More people speak Swahili than Korean or Italian.This week reporter Daniel A. Gross investigates how Swahili became a prominent language on the African continent and increasingly around the globe.