We see huge potential to impact millions of learners in India: Duolingo's Severin Hacker

Eventually, we found a way to work around the same. Now we have advertising and we have subscription. The subscription has two features—it removes ads and it gives you features that allow you to progress faster in the course. Essentially, users are paying for convenience.

We are also adding a second subscription tier, which is Duolingo Max, which has all of our AI-powered features.

Q. But to get subscribers, you would have needed quite a bit of marketing…

Actually, no. Initially, it was simply word of mouth. People were telling each other, ‘If you want to learn German or Spanish, use Duolingo.’ Now, of course, we use marketing channels, where social media platforms like TikTok play a significant role.

Q. Duolingo’s mascot, Duo, has become an iconic symbol of the brand. How did the idea for Duo come about?

Luis wanted to have a mascot, to have a personification, but we didn’t want it to be a human. So we hired a design agency to come up with a mascot. They gave us two options—one was a little cute robot and the second was the owl. We all preferred the little robot, because we were all nerds. But then we asked a bunch of people and they all told us to go with the owl. That's how the iconic 'Duo' came up. And that is also our application Icon, which changes basis the users' behaviour.

Q. The Duolingo English Test (DET) is a relatively new feature. What led to the decision to venture into language proficiency testing?

Both of us (von Ahn and Hacker) had to appear for TOEFL which at the time was the pen-paper version. Luis had to travel to a different country to appear for the exam. It was a painful experience for anyone who had to take the exam. In fact, a lot of our users also asked us for a feature like this. Many said that it's great that you teach English, but I still have to appear for an English-language test like TOEFL or IELTS. They would ask if we could provide them with an alternative.

Internally, we had this hackathon where one of our engineers came up with a novel way of measuring someone's vocabulary in a language like English. For instance, it gave you a bunch of words, some of them were real English words and some were fake English words that don't exist in the dictionary—you had to tell which one is real and which one is fake. That’s how you could measure vocabulary.

It was very primitive, but that was kind of the first part of a solution that eventually evolved into the development of DET. The test is entirely AI-driven, which means the content is adaptive, it's much shorter than TOEFL, and you don't have to make an appointment, you don't have to go to a test centre, you can take it at home. It's way more convenient and affordable.

Also, if you think at a very high level, what is education? People mostly focus on just the content and what you learn immediately, but it's actually much broader. If you get a degree it's a signalling—that a university is providing you with a certification stating that you have proficiency in a certain subject. That's how the English test fits in with Duolingo. We don't only want to teach, we want to build the full education solution, which includes assessment. That's why we built the Duolingo English Test.

Q. Since DET is quite different from the core Duolingo platform, what were some of the biggest challenges in getting it accepted by universities? Were there specific hurdles—such as regulations or credibility concerns—that the team had to overcome?

Yes, it took us a long time to get universities to accept DET. The first one to accept it was Yale. We sold it to them, and most universities, stating that it was a much better solution for a test taker, and if they want to reach a global audience, DET is much more accessible. It still took us a while to get through to most. But then the Covid-19 pandemic happened. And in 2020-2021, we were the only option available because all test centres were shut. That was a blessing in disguise, because it helped a lot with our growth and university acceptance. Currently, over 5,700 universities are accepting the DET world over.

Q. What kind of potential does a test like DET have with Indian students?

English here has become the global language of business, science and culture so the demand to learn it is skyrocketing. According to the British Council and UNESCO, millions of Indian learners are now looking for ways to master English and that’s where platforms like Duolingo come in.

Even though India claims to have the largest population of English speakers globally outside of the United States, at 129 million English speakers across all 29 states, less than 10 percent of the total population speak English. In other words, 90 percent of the population is in need of English learning resources. Hence, it’s no surprise that English is the top language of choice for Indians to learn on Duolingo.

India’s English learner market is unique—the country has a large, young population—over 50 percent of India’s population is under the age of 25 and many of them are eager to learn English, not just for academic purposes but for career advancement as well. English is increasingly becoming a necessity, not just a skill and this is driving demand for language learning tools like Duolingo.

One of the key challenges, though, is that many learners in India don’t have access to high-quality, affordable language learning options. With the Language app and the Duolingo English Test, we’re providing a solution that is accessible, affordable and flexible both in learning English and demonstrating proficiency in it. For us, this presented both a challenge and an incredible opportunity.

Another thing that stands out in India is the diversity of learners. English proficiency isn’t just about formal education—many learners are self-taught or learn English informally through movies, music or online content. This is one of the reasons why we’ve focused on making Duolingo fun and gamified because we know that for many learners staying motivated and engaged is the biggest hurdle. We see huge potential to impact millions of learners here, helping them achieve their goals whether that’s acing an English proficiency test, improving their career prospects or simply feeling more confident communicating in English.

Q. How are you integrating GenerativeAI within Duolingo?

We feel that with GenAI we can teach a lot better. One of our weaknesses in the product for a long time was practising conversational skills. The technology was not really ready for that, but now it is. We have this feature called 'Video call with Lily'. This feature is completely AI-driven and it allows you to converse in a language that you're learning, and it's really good at actually teaching you how to have a conversation.

With AI we are building features that make learning a lot better. Second, AI is helping us generate content across the app—basically, 90 percent of our content is automatically generated. Third, we are using AI to make the whole operation far more efficient—from coding for software engineers to customer support. Lastly, since we are expanding to newer subjects, we are using AI to generate newer content for those skills as well. We want to be AI-first in every possible way.

Also read: Generative AI in the classroom: Next edtech evolution

Q. Looking back, do you wish you had done something differently in how you built the company?

There's two things I think we could have done better. We should have hired senior leaders early on. We hired some of the fresh graduates from Carnegie Mellon when we should have hired management leaders. The second is we waited too long to take monetisation seriously. We were idealistic for way too long, I feel.