After helping a friend start a Spanish Club, I became addicted to Duolingo, the free language app. Then I discovered the power of free, artificially intelligent assistants.

The company confirmed to CNBC that there's been a 216% increase in Mandarin learners using the app compared to a year earlier ...

"First of all, the Chinese are so nice, they're so sweet and so welcoming. They've over here teaching us Mandarin." ...

Duolingo shares popped on Thursday following a large spike in users signing up to learn Mandarin in conjunction ... For context, Spanish, one of the most popular languages on the app, has seen ...