For several centuries, people have tried to write Fulani – which is spoken across a huge swath of West Africa, from Senegal to Cameroon – with adaptations of the Arabic and Latin alphabets, neither of which can properly represent Fulani’s sounds; neither ever fully caught on. So Fulani remained mostly a spoken language, its speakers taking their school classes in French or English. In 1990, two Guinean teenagers developed a new script, and they’ve spent a quarter-century spreading it.