How Duolingo sparked a language revolution

Duolingo saw language learner numbers rocket in lockdown. But what’s really surprising is that it’s us in the UK who are reaching out to communicate with the world. Steven MacKenzie speaks to founder Luis von Ahn


It came as news to many in Scotland, including the country’s former first minister, that Alba, the nation’s name in Scots Gaelic, is pronounced differently from the way it might look to English speakers.

Launching his new Alba Party last month, Alex Salmond stirred up sections of social media by seemingly not knowing how to correctly say the name of the country he was returning to herald independence for.

Of course, it doesn’t take much to cause a stooshie in Scottish politics, but the symbolism of a single word is indicative of so many things in post-Brexit Britain and where we sit in a simultaneously globalised but increasingly segregated, far from post-Covid, world.

Words matter. Communication, whether it’s conveying lifesaving messages or keeping us connected, is more important than ever. Language shapes how we think and is core to our identity and technology is quietly powering a learning revolution that is having massive cultural and political implications.

Given Britain is famously bad at speaking foreign you’d think we may be sitting this innovation out. But not according to the man behind the most popular language-learning app, Duolingo.


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“We hear this reputation about the UK but it’s our third largest country,” says Guatemalan tech tycoon Luis von Ahn. “The third or fourth,” he corrects. “Fourth after Brazil – but it’s neck and neck.”

Duolingo is the most popular education app – with the highest revenues. The vast majority of users don’t pay a penny for its courses available in dozens of languages from Arabic to Vietnamese, with some fictional ones thrown in like Klingon and High Valyrian from Game of Thrones.

It gamifies learning. Courses are structured like levels on a video game. You earn crowns for regular use and get chirpy little reassuring sounds when you answer correctly. You become engaged and addicted in a way you never did learning past participles at school.

And it works. A recent study compared novices who had reached a certain stage on Duolingo with students learning a language at college and found that users who had reached ‘checkpoint five’ – about halfway through a course – had the same proficiency as students who had studied for four semesters at university, reached in half the time.

Three hundred million people are currently using it to learn another language, 15 million in the UK.

The reasons people are learning at home and abroad differ. Fortunately for us, English is the world’s lingua franca and in 121 countries where Duolingo is used, it’s the language most people are learning. In the UK, the most popular languages are Spanish, French and German – reflecting the school system.

But Duolingo is providing access to a whole variety of languages and changing the reasons we want to learn them. When K-pop band BTS toured the UK, there was a 50 per cent increase in people learning Korean. When the Tokyo Olympics should have been on, Japanese was popular.

Recent growth has also been driven by the same factors driving everything else: Brexit and Covid.

In an act of linguistic solidarity, Duolingo saw a Brexit bounce of 24 per cent in new learners the week before Article 50 was triggered. And in the week immediately after lockdown, the UK saw a 296 per cent increase.

Duolingo has offered a place to broaden our horizons when actual horizons remained out of reach in lockdown.

“We’ve seen an uptick in our users in two big broad categories,” says von Ahn. “A lot of schools are running remotely and teachers are using a lot more tools like Duolingo. And we’ve seen a lot of people who are basically at home deciding to do something positive with this time.

“Our Covid growth in the UK was double that of the global growth, so we grew everywhere in the world but in the UK we did twice as much. So if you asked us: just looking at your data do you think the UK has no interest in languages? I will tell you that is not supported by our data.”

And von Ahn’s data processing skills are second to none. The unassuming 42-year-old is speaking to The Big Issue from Pittsburgh, where he works at Carnegie Mellon University. A crowdsourcing pioneer, he’d sold two companies to Google by the age of 31 including reCAPTCHA, which every internet user is incredibly familiar with, for an undisclosed eight-figure sum [see sidebar on opposite page]. In 2012, with one of his students, Swedish-Swiss Severin Hacker, he founded Duolingo.

Today von Ahn is learning three languages: Portuguese, French and Japanese. What Brits are choosing to learn is fascinating.

Learners of languages here have until recently been those forced to do a bit of French or German in high school. We’d only take up a language in later life if we wanted to learn a few words before going on holiday in case we visited a restaurant without pictures on the menu.

Now people are learning a language to discover more about themselves, their country, their culture. In 2020, the fastest growing language in the UK was Welsh, with 1.6 million learners. The Scottish Gaelic course has also been staggeringly successful, with 570,000 learners within a year of the course’s launch –that is 10 times the number of native speakers. One of them is probably not Alex Salmond.

Similarly, in Spain people use Duolingo to learn some Catalan. Navajo is available, a Maori course is set to launch soon. Duolingo is helping revive languages that were at risk of becoming extinct but are at the heart of a country’s culture.

However, von Ahn admits he isn’t particularly interested in people learning for a hobby. Like billions of others, he knows that English is a lifeline.

“English is not my native language,” he says. “Learning English changed my life quite a bit.”

Von Ahn attended an English-language school in Guatemala, but knows many others weren’t so lucky and is working to break down education barriers.

He tells a story to illustrate his ambition.

“There was a weird week maybe three or four years ago, where we learned that Syrian refugees were using Duolingo all across Europe to learn the native language of each of the countries, to be able to get jobs. That same week through a Reddit post, we learned that Bill Gates was using Duolingo to learn French.

“Normally a billionaire has significantly better access to educational opportunities. The fact that the same system was being used by Syrian refugees as by, at the time, the richest man in the world is the thing that makes me the proudest.”

When von Ahn and Hacker started developing Duolingo, neither had any experience of teaching English. However, approaching the challenge from a computer scientist’s perspective changed not just how people are learning languages, but how courses are developed and taught.

“When we were starting to work on Duolingo we didn’t know anything about teaching language so we went to read a bunch of books,” von Ahn explains. “We ran into a little bit of a problem because the books contradicted each other. One of them was like, this is the best method to teach a language, then another one also claimed they had the best method – but it was different.

“We had very simple questions like, for example, when you’re teaching Spanish, should you teach plurals before adjectives or adjectives before plurals?

“Over time, we realised that we could actually learn the answers by doing tests on our users. For the next 50,000 people that sign up, to half let’s teach them plurals before adjectives, and to the other half adjectives before plurals. Then we measure which ones engage more and learn better.

“There are millions of these little, little decisions that you have to make. And one thing that’s amazing is this varies by language.”

Using information in this way transforms how Duolingo teaches, and its courses are constantly evolving depending on data that is being collected at levels never before possible.

“Users of Duolingo answer about half a billion exercises every single day,” von Ahn continues. “We can look at patterns and make improvements. Compare with 30 years ago, how would you improve how you teach? A teacher would teach a class, OK, this semester I’m going to teach plurals before adjectives. It would take a whole year and you weren’t even super sure whether it was better or not because you have a sample of 30 kids.

“Now we can do this type of stuff in a matter of days. This is why I’m very excited about, you know, basically all of education.”

The ever-ambitious von Ahn has a vision to apply the lessons Duolingo has taught across other subjects. This could dramatically change education around the world. Anyone with a smartphone could have free access to the very best learning tools.

Von Ahn wants to create a society where money can’t buy a better education. “That is our goal. You can have access to the best. And this is just on your phone and it’s free.

“It is, of course, going to take a while. But already we have launched another app called Duolingo ABC, where the idea is to teach kids how to read in their native language. Again, it’s a fully free app.

“A lot of what we’ve learned to teach languages we can apply to other domains. Learning maths is similar to learning a language because it’s basically a lot of drills and repetition, and I think we’ve gotten very good at keeping people engaged in doing that over and over again.

“Maybe not all domains, learning philosophy is pretty different from learning a language. If you want to be a doctor you probably still want to go to a really good university.”


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