The Green Owl Is Very Fluent

Duolingo has a cult following and a grandiose mission. Can the language learning app educate the world for free and still satisfy Wall Street?

- Bill Gifford

After dinner on Aug. 23-a date he will never forget-Tobi Fondse pulled out his phone to do his daily Duolingo. He was studying French on the language-learning app so he'd be able to order croissants au jambon and bière à la pression on his frequent visits to France, "instead of having to point at things," says the 50-year-old Dutch IT consultant.

He'd tried Babbel, Busuu and other language apps but preferred Duolingo because its lessons were fun. They didn't feel like a chore. He and his wife, Marisa, had completed at least one lesson for more than 400 consecutive days, placing them among Duolingo's most dedicated paying users. "I'm deadly serious about learning French," he says.

But as the app opened that summer evening, the lesson modules he was used to suddenly vanished. Duolingo's mascot, a cheerful and slightly passive-aggressive green cartoon owl named "Duo," flitted across his screen to announce a major change: Instead of picking and choosing which lessons they did-matching vocabulary words, listening to brief stories, learning how to order food or shop for clothes-Fondse and other users would now be required to follow a prescribed path from lesson to lesson. It looked like some kind of children's board game, and worse-it felt like homework.

Fondse was stunned. Then he got angry. Now "you always have to do what the app tells you to do," he says, bitterly.

So he decided to fight back, creating the Twitter account @Duo_is_sad, along with a petition, to beg the company to reverse the update.