A fortune teller once warned Zhou Youguang he would not live past 35. The prediction was plausible, as Zhou himself later noted. Average life expectancy in China was then around 30. He had experienced tuberculosis and depression and within a few years would narrowly escape death in a Japanese bombing raid that killed the man beside him. Yet his eventual death came the day after his 111th birthday.

By then he had fewer than 50 peers worldwide. The rest are known primarily for their survival, and Zhou had a variety of explanations for his own longevity: modern medicine, eating when hungry and sleeping when tired, and simply the fact that “God has forgotten me”, a remark reflecting both his humility and his humour. But he had staked his claim to a place in the history books more than half a century before, as “the father of pinyin”, having established what became the international standard for romanisation of Chinese.

It is thanks to pinyin that we now read about Beijing, not Peking. The system helped literacy rates in China to rocket: children learn pinyin as a stepping stone to characters because – unlike these – it corresponds to the sound of words. It also became “a bridge to speech between Chinese people”, Zhou pointed out, helping Putonghua, or standard Chinese, to spread.

“Before, I met a Cantonese and a Hokkien in foreign countries and couldn’t communicate – I had to speak English to them. Without an alphabet you had to learn mouth to mouth, ear to ear,” he told me when I interviewed him at his modest third-floor apartment in Beijing in 2008. He was a mere 102 then: fascinating, wry, delightful company and unnecessarily apologetic for the rustiness of his (fluent) English.

He was born Zhou Yaoping – he adopted the pen name “Youguang” because he wanted to “bring light” into the world – to an official’s family in Changzhou, eastern China. The Qing dynasty still ruled. But within five years, China would collapse into turmoil: Zhou would live through warlordism, the rise of the Kuomintang, foreign occupation, civil war, the communist revolution and all that followed.

He studied at St John’s University and then Guanghua University in Shanghai, graduating with a degree in economics; he had minored in linguistics. A fellow student was Zhang Yunhe, one of four famously accomplished sisters, whom he married in 1933. After the Japanese invasion they fled to the wartime capital, Chongqing, where their young daughter died of appendicitis because they could not reach the hospital in time.

Yet even then he maintained hope. “When you encounter difficulties, you need to be optimistic ... The pessimists tend to die,” he told the AFP news agency.

In 1946, he moved to New York, where he worked for a Chinese bank on Wall Street and met Albert Einstein via friends at Princeton. But when the communists took power in China three years later, Zhou rejected offers from American banks and chose to return, like so many idealistic intellectuals who hoped to build a new and better China. He became an economics professor in Shanghai.

Soon afterwards came his greatest piece of luck. Zhou Enlai, the country’s premier, had met him in Chongqing and now wanted him to oversee a reform of the written language. Zhou Youguang, who regarded his studies of language and linguistics as a hobby, allowed himself to be persuaded, and pinyin was launched in 1958. That shielded him from the worst when Mao Zedong unleashed the vicious anti-rightist campaign a few years later and economist friends were persecuted; several killed themselves.

Zhou Youguang and Zhang Yunhe on their wedding day, 30 April 1933. Photograph: The Paper

But after the Cultural Revolution broke out in 1966, Zhou was exiled to a labour camp in the countryside. In later life he chuckled with friends about his overqualification for the role to which he had been assigned: the former banker and father of pinyin had been set to work scaring birds away from crops.

Following his rehabilitation, he oversaw the translation of the Encyclopaedia Britannica, earning himself the nickname Encyclopaedia Zhou. Officially he retired at 85, but at home he averaged an essay a month. The best tonic was remaining curious and continuing to learn, he said. His embrace of new ideas included helping Sharp to design the first practical electronic Chinese typewriter. The device showed only a single line of text at a time, but he wrote on it until the last; his friend the sinologist Victor Mair recalls him storing it as though it were a precious relic, unwrapping it each morning and setting to work with relish.

The spread of computers and smartphones brought a fresh role for pinyin, which many people rely on to input characters. Zhou wrote at least 10 books after turning 100, but several were banned as he became increasingly outspoken, apparently concluding he had little to lose. In 2011 he told NPR radio network that he hoped to live long enough to see the Chinese authorities admit that the bloody crackdown on Tiananmen Square’s pro-democracy protests in 1989 had been a mistake.

“History misled us,” he said, when I asked him about his decision to return to China in 1949. Yet he did not regret coming home, he maintained. Despite the traumas he witnessed and endured, he believed he was where he belonged.

Zhang Yunhe, who became an eminent scholar of kunqu, one of the oldest forms of Chinese opera, died in 2002. Their son, Zhou Xiaoping, died in 2015. Zhou is survived by a granddaughter.

• Zhou Youguang (Zhou Yaoping), language scholar, born 13 January 1906; died 14 January 2017