Starting today, the free language-learning app Duolingo is offering a brand new ... If you already know some Chinese, there's a placement test that will allow you to skip over early parts of ...

Language-learning app Duolingo makes around $500 million annually, despite offering all of its lessons for free. WSJ explores how the company is using AI and A/B testing to keep users hooked.

Its solutions include The Duolingo Language Learning App, Super Duolingo, Duolingo English Test: AI-Driven Language Assessment, Duolingo For Schools, Duolingo ABC, and Duolingo Math. It has three ...