She wanted to talk to her grandmother. So she built an AI to practice with - and accidentally found a market of millions.
Jennifer Liu. Engineer first, CEO second - the kind of founder who would rather ship the tutor than describe it.
Open Toko and you will not find flashcards, a streak counter, or a cartoon owl guilt-tripping you into a lesson. You will find a conversation. You say something in English - clumsy, hesitant, accented - and an AI answers back, then quietly points out where your grammar wobbled. There are more than 500 topics, from ordering coffee to surviving a job interview, and for a huge number of learners in Taiwan, Hong Kong, Vietnam and Thailand, this is the least terrifying place they have ever practiced a language.
That is the product Jennifer Liu leads as cofounder and CEO. Toko is an AI English tutor aimed squarely at East Asia, and it has done the thing most edtech apps only put on a pitch deck: it climbed to the top five education apps in four countries and holds a 4.9-star rating across more than 20,000 reviews. It went through Y Combinator's Winter 2022 batch. It runs on a small team out of New York. And it started, improbably, as a way to talk to a grandmother.
Liu's bet is a specific one. Most language apps optimize for the parts of learning that are easy to measure - words memorized, lessons completed, days in a row. Toko optimizes for the part that actually stops people from speaking: the fear of sounding foolish in front of another human. Swap the human for a patient machine, and the embarrassment evaporates. What is left is practice.
Every good company has a first sketch. Toko's was an AI grandmother.
During the pandemic, Liu - Taiwanese American - spent more time with family and hit a wall. She could not comfortably hold a conversation with her own grandmother in Mandarin.
So she and Erica Du wired up GPT-3 into an AI grandma - "GPT 奶奶" - to practice Mandarin. This was well before large language models were a household phrase.
The demand, it turned out, ran the other way. Far more people in East Asia wanted to learn English. The side project pivoted, and Toko was born.
During the pandemic, I spent more time connecting with family, but I struggled to talk to my grandma in Mandarin.
Liu did not arrive at edtech by accident. At MIT, studying computer science and engineering, she was a Google Undergraduate Research and Innovation Scholar. Her research project had a title that reads, in hindsight, like foreshadowing: "The Future Textbook." Under advisor David Karger, she built NB, a collaborative annotation platform that let students ask and answer questions directly inside a PDF, with embedded exercises and wiki-style consensus notes. She was, even then, trying to make learning less lonely.
She also worked with MIT's Global Startup Labs in South Africa and its Ubiquitous Games group, building accessible mobile educational games. The pattern was set early: technology, education, and a stubborn interest in the people usually left out.
After MIT came Quizlet, where she joined early as an engineer and grew into a product manager. There she led teams around AI-powered learning, mobile subscriptions and international growth - a near-perfect syllabus for the company she would eventually run. She optimized front-end performance, hunted technical bottlenecks, and learned how a learning product actually scales across borders. Somewhere in between she founded Uplevel, a coach-matching concierge service, testing her instinct that the right human - or the right stand-in - changes everything.
By the time GPT-3 arrived, Liu had spent a decade circling the same question from every angle: how do you help someone learn without making them feel small? Toko is her most direct answer yet.
The old way to learn a language on your phone is to memorize. Tap the right translation, keep the streak alive, collect the badge. It works for vocabulary and fails at the moment that matters - the moment you have to open your mouth in front of someone.
Toko's design flips the priority. The core loop is talking, not tapping. An AI plays every awkward first conversation you would rather not have with a stranger, and it never sighs, never corrects you rudely, never remembers your mistakes tomorrow. The grammar feedback is instant and private. The 500-plus scenarios mean you can rehearse the exact conversation you are dreading before you have to live it.
That is why the numbers look the way they do. A 4.9-star average across 20,000 reviews is not a marketing figure - it is what happens when you remove the single biggest reason people quit a language app: shame.
Make becoming a confident, fluent English speaker accessible and judgment-free for learners across East Asia and beyond - with AI conversation, not vocabulary drills, at the center of it all.