One fact we're particularly proud of is that there are more people learning languages on Duolingo in the US than there are people learning languages in the entire US public school system.

I usually make to-do lists with timelines, and pen and paper does the trick for me.

[Captchas] are not only annoying, but they kill 10 seconds of your time.

Before the Internet, coordinating more than 100,000 people, let alone paying them, was essentially impossible. But now with the Internet, I've just shown you a project where we've gotten 750 million people to help us digitize human knowledge.

It's hard to think of a time when I'm not working, but when that is the case, I like to travel and eat good food.

People are good at figuring out what's attractive, and computers are good at quickly searching and finding. You put them together, and bang!

Because education is such a broad area, I chose to focus on language learning.