The first language used on Yang Weiyun's livestream isn't always Chinese. Sometimes it's a thumb, a heart, or a crying face.In the small room where she holds her online classes in Huainan - a former coal-mining city in eastern China - these symbols have become a kind of classroom code.A thumbs-up means, roughly: 'I understand.' A heart means: 'Thank you, teacher.' And a crying face translates as: 'I still don't get it.'Yang, 76, has become fluent in emoji-speak.Many of the people watching her cannot yet type the words they want to say: some are adults who have lived much of their lives without being able to read fluently, while others know the basics but still struggle to connect sounds and words.The remainder can read but would like to improve their Mandarin enough to travel, speak with customers, or become more comfortable during everyday conversations. As she addresses her students, Yang leans toward the old mobile phone that serves as her camera, opens her mouth wide, and turns each vowel into a performance. Yang Weiyun, 76, doing a livestream on Douyin, the Chinese version of TikTok'A,' she says. Then again. And again, with her lips exaggerating the shape of the sound so that someone watching from a field, a warehouse, a truck cab or a wheelchair can follow her. A single syllable may take 20 minutes, and each lesson moves slowly – at a pace that seems almost defiant on a platform built for speed.There is little in the room to suggest the accoutrements of the modern internet, such as music, filters, theatrical lighting or goods for sale. Yang has a worn blackboard, a phone and the voice of someone who spent most of her life addressing children who were just beginning to read.She begins each daily class at 4.30pm, regardless of the number of viewers. Some days, fewer than 10 people attend, but other times there are many more.'After teaching for more than 50 years, I never imagined I would have my largest number of students after 70,' she says.Yang did not set out looking for adult learners. When she first started her livestream in May 2021, she thought she would be giving children preparing for primary school lessons in pinyin – the phonetic system used to spell out the sounds of Mandarin using the standard Latin alphabet - and basic Mandarin characters.After all, that was the life she knew.Yang's previous career as a primary school teacher began in 1971 at the age of 21. The coal miner's daughter remembers being so nervous that she sweated through the lesson. Teaching, she believed at the time, was 'the most sacred job in the world.' Yang's handwritten teaching notes consist of classic poems with pinyin markings and modern Chinese translationsShe taught for three decades and retired in 2000 but found it hard to stop. After returning to Huainan, she continued working in kindergartens. Only in early 2021, when illness forced her to rest, did she find herself away from a classroom.For Yang, this enforced convalescence felt like punishment.Then came Douyin, the Chinese version of TikTok. Watching others teach singing, dancing, calligraphy and painting on a livestream, Yang asked herself: 'Why can't I teach pinyin?'Her children worried about her health, so she learned in secret.To master the art of livestreaming, she visited the livestream rooms of established streamers, studying everything from audience engagement and lighting techniques to the technical skills required to run a seamless broadcast.Her instructors, she emphasises, were not education specialists, but sellers of consumer goods, from cosmetics and clothes to chicken and fish. Sometimes she bought things simply so a host would answer her technical questions.During her first ever livestream, only family members joined in, but Yang – undaunted - continued the session for more than two hours.After a month or so, her livestream began drawing as many as 10,000 viewers. Yet for Yang, the real turning point wasn't the surge in traffic, but a question. Yang interacting with viewers​ following her lessonsIn 2021, on the night of the Dragon Boat Festival – a traditional Chinese holiday - Yang had been teaching for hours when a viewer connected with her and asked: 'Teacher, I'm 50. Is it too late for me to learn to read?'Intrigued, Yang asked those in the livestream room how many viewers were also adults who wanted to learn characters.The comments began to fill with 'raised hands' emojis. What she initially believed to be a children's class was in fact a group of grown-ups, many of whom had spent much of their lives on the margins of literacy.For truck driver Liu Xianzhi, from Baotou in north China's Inner Mongolia Autonomous Region, this had practical consequences. Unable to read cargo forms or road signs, he had often taken wrong turns and driven dozens of extra miles.After studying with Yang for three years, he learned more than a thousand commonly used Chinese characters. When he managed to help his son complete the documents required to apply for university, he cried tears of joy.Another student, Fang Meizhang, a 75-year-old woman from Jiangxi Province in eastern China, already knew Chinese characters but had long been embarrassed by her inability to speak standard Mandarin. After four years of practice, her new language skills helped her become a host at a local cultural performance.Yang's method remains consistent, focusing on repetition and mastering the basics. Learners with some language skills practice spelling out sounds and recognising characters, while others move on to simple poems and elementary texts.In her classroom, literacy is not an abstract virtue, but a lived reality: a cargo form, a road sign, a conversation with a customer, a university enrolment form for a son, or a name written without assistance.One of Yang's students, Jiang Yan, a girl with cerebral palsy living in the eastern province of Jiangsu, once used her nose to share emojis during lessons. She had initially believed studying was pointless because she was unable to stand, but Yang told her that learning words would allow her to tell others what she needed. Yang busy with her lesson planningSince then, Jiang has learned several hundred common characters and can sound out several words clearly.One of the things that makes Yang unusual is her decision not to charge her viewers.She has turned off tipping and doesn't sell goods or offer paid study materials. In a livestream economy where attention is often treated as a source of revenue, Yang is happy to simply pass on her wisdom.In 2023, she was honoured as one of China's 'silver-haired edu-streamers,' a group of elderly online educators that also included academicians, professors and retired teachers.While some explained the depths of the universe or the mysteries of the sea, Yang taught the basic building blocks of language.The pairing was revealing. Knowledge doesn't only begin at the frontiers of science. Sometimes it's about something as simple as being able to read a road sign, fill out a form, or tell another person - in writing - what they need.Yang's initial surge in viewership hasn't always been sustained. Some days, her audience falls back to single digits.But the class continues. A comment appears: 'Teacher Yang, I'm late. I was weeding in the field.' Another reads: 'Teacher Yang, today I learned to write my name.'Original story by Ma Yunfei and Zhu Qing