“Those letters were very difficult to read even if you were educated in Arabic,” Abdoulaye said. “You could hardly make out what was written.”

So, in 1990, the brothers started coming up with an alternative. Abdoulaye was 10 years old; Ibrahima was 14.

After school, they’d shut themselves in their rooms to draw, filling blank composition books they brought home from the classroom with the shapes that would make up their new alphabet. They’d take turns drawing letters, and together, assigned sounds to the shapes they came up with.

Six months later, they had a working script. Like Arabic, its 28 letters were written right to left. But unlike Arabic, whose short vowels are written as diacritical marks above and below letters, the script assigned its five vowels proper letters. It looked something like a cursive version of Ethiopic. Ibrahima and Abdoulaye’s parents started taking their project seriously, and invited one of their father’s relatives, who had an influential post in the local government, for a demonstration.

The visitor tested them: With Abdoulaye in the other room, Ibrahima would take dictation. When Abdoulaye returned, he read aloud what his brother had written. They switched and repeated the test. Over and over, the brothers consistently read out the right sounds, even those unique to Fulani. Crucially, they spelled the same complicated words in the same ways, independently of one another.

The visitor turned to their father. “Oh, yes, these kids are being serious,” he said.

It’s not every day that a new alphabet is born. The scripts in widest use today—Latin, Chinese, Arabic, Devanagari, Cyrillic—are all at least a thousand years old, and they each evolved from earlier alphabets. Creating a new script and getting it adopted widely is an enormous challenge.

The Cherokee alphabet is a notable success story. In the early 19th century, a man named Sequoyah created a script for writing his native Cherokee, which until then had only ever been spoken aloud. At first, many thought his scribbles were meaningless, and that he was playing tricks on people. But in a blind test not unlike the one Abdoulaye and Ibrahima would complete more than a century and a half later, Sequoyah and his daughter, who had also learned the alphabet, proved that the symbols they’d drawn actually represented words by reading what the other had written.

Sequoyah began to teach others to read and write, and his simple alphabet spread quickly among tribe members. In 1828, just seven years after Sequoyah invented the alphabet, the first-ever Cherokee-language printing press was used to publish the Cherokee Phoenix, a newspaper that was distributed for free to Cherokee speakers who didn’t know English. The press helped standardize and simplify the script, and made it possible to quickly publish newspapers and books.