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

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

I watch a lot of TV. That's how I spend most of my time outside of work. If I had more time, I would fill it 100 percent with watching TV.

The question that motivates my research is, if we can put a man on the Moon with 100,000 [people], what can we do with 100 million?

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.

Every time you buy tickets on Ticketmaster, you help to digitize a book.

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