Park Han-sol reports on Korea's financial regulators, along with fintech and insurance. She previously wrote about the art world, from biennales and exhibitions to fairs and auctions, with a focus on Seoul and the figures shaping the scene. Before joining The Korea Times, she spent a year at ABC News' Seoul bureau, contributing to coverage of major Asia-Pacific events.
INTERVIEW UC Berkeley graduate creates AI-powered app to make learning Korean more immersive
AI-powered language learning app Teuida / Courtesy of Teuida
By Park Han-sol
How Teuida turns language lessons into real-life simulations
For as long as he could remember, education was where Jang Ji-woong imagined himself making a difference.
He enjoyed working with children, but he found himself thinking less about classrooms and more about access — how to bring learning opportunities to communities often left out.
“I often thought Korea’s rapid modernization was driven by the extraordinary emphasis placed on schooling,” Jang said. “But having a strong desire for education alone isn’t enough, especially today. I kept wondering how people in underserved regions could gain stable access to quality education.”
That interest took him to UC Berkeley, where he studied political science with hopes of eventually working for an international organization, helping expand access to learning through projects ranging from school construction to online programs.
After graduation, however, his path took a different turn, as he joined a Silicon Valley e-learning startup before moving into global commerce marketing in Korea. But the question that had first drawn him to the field never entirely went away.
While weighing his next career move, Jang began exploring startup ideas. A government-backed entrepreneurship program gave him the opportunity to turn one of them into reality in 2019.
The venture that emerged became Teuida, an artificial intelligence (AI)-powered language-learning app now used by millions around the world.
Teuida CEO Jang Ji-woong / Courtesy of Teuida
Seven years after its rollout, the platform has surpassed 6 million cumulative downloads. American users account for roughly 30 percent of the total, followed by users in India and Vietnam.
While the app offers lessons in Korean, Japanese, Spanish and French, Korean remains its most popular language by a wide margin. In fact, Teuida consistently ranks first for Korean-language learning app in the U.S. and the U.K.
When Teuida was launched in 2019, many still questioned whether learning Korean could support a sizable business. The market has since expanded rapidly, helped in part by the growing global visibility of K-entertainment and culture.
“It has certainly been a major driver,” Jang said. “With the likes of BTS, ‘Squid Game’ and ‘KPop Demon Hunters’ reaching wider audiences, people naturally became curious about the country behind them. And particularly in Western countries, I’ve noticed that when people become interested in a place, that curiosity often extends to the language as well.”
But Teuida was hardly the only app riding that cultural wave.
What helped it stand out among its competitors was its singular focus on speaking — not memorizing vocabulary lists or completing grammar drills, but getting users comfortable enough to actually hold a conversation.
Powered by AI speech-recognition technology, the app places learners inside interactive video scenarios where they speak directly to native speakers on screen. Rather than chatting with a text bot, users navigate real-world situations by responding aloud, with the AI evaluating pronunciation and conversational context before advancing the story.
The result feels less like a lesson and more like stepping into a role.
One storyline follows a chance encounter in Korea that unfolds into a budding romance over a series of conversations. Another places users in the shoes of an exchange student navigating group projects and university campus life. Others simulate everything from office summer internships to ordering food, riding the subway or visiting major landmarks.
“The way Teuida teaches languages is through interactive simulation,” Jang said. “Learning a language is one thing, but we also want people to experience what life in that country actually feels like. Even if they’ve never been to Korea, they can learn how to buy a subway ticket, navigate a hospital visit or travel around places like Bukchon.”
The company’s goal is not perfection but confidence in communicating in everyday situations.
Lessons are designed so that even complete beginners can start speaking without first mastering grammar rules or writing systems. A user who relies solely on Teuida may not become fluent in reading or writing, the CEO acknowledged, but should be able to recognize what sounds natural in a given situation and respond accordingly.
That narrow focus is intentional. Rather than trying to cover every aspect of language learning, the app concentrates on helping users overcome the hurdle of speaking, leaving other areas to the countless resources already available elsewhere.
Such growth has been steadily attracting attention beyond Korea. In May, Teuida was invited to present at Google’s annual developer conference, Google I/O, where the company met with executives overseeing Google’s XR and U.S. Play businesses.
Jang believes the company is still in the early stages of a much larger opportunity.
“Advances in AI and the ease of international travel have lowered barriers in many ways,” he said. “At the same time, demand for language learning is growing rapidly. If we move well and move quickly, there’s still significant room for growth.”