Duolingo is the Most Dangerous App for Untrained Language Learners

The most well-known language app poorly uses its potential

Mathias Barra
The Language Learning Hub
5 min readJul 27, 2021


Photo by Nick Fewings on Unsplash

Duolingo might be the language-learning app I hate most.

Despite being the most downloaded Education app almost every year, it’s also one of the reasons so many people fail to learn a foreign language.

As Duolingo is preparing to go public, I think it’s time to set things straight. It’s time to explain the downsides of Duolingo so nobody falls prey to their marketing and lies it makes us believe.

As a polyglot who’s learned 6 languages over the past decade, I’ve played around with it countless times. I even completed the Korean course two years ago.

I’ll be as honest about its ups and downs as I can but be aware it is still only an opinion. I hope it can serve you.

Duolingo’s Study of its Results is Full of Lies

Duolingo claims it’s more useful than language University classes. It’s often said that 34 hours on Duolingo equals 1 semester of classes. On paper, it seems great. When you dig deeper, you realize the lie.

They did a study based on English learners of French and Spanish and showed that 4 semesters of classes, or about 240 hours of classes, helped students reach about the same level as 120 hours of Duolingo study. There are a few things to not overlook, however:

  • The study focused on two languages alone and ignores the fact that learning Japanese or Arabic would take a lot more time for English speakers.
  • They overlooked the fact that university classes aren’t just about language but also about culture. Learning a language without learning its culture is like learning to surf on land. You could put it in practice but you’d fall down sooner than later.
  • The study was only made on passive skills, reading and listening, which means they compared classes where both active (writing and speaking) and passive skills were taught. The time comparison is therefore flawed.

There are many other problems with this study but they are often overlooked due to their overwhelming presence online when searching for…



Mathias Barra
The Language Learning Hub

French polyglot speaking 6 languages. Writer. Helping you learn languages. Get my new ebook → https://linktr.ee/MathiasBarra