SHI Junguang has no teaching diploma, but the former rice farmer got a language-teaching job with a verbal reference from his grandmother about his command of Manchu - once used in imperial documents but now on the verge of extinction.

Fewer than 100 people can speak fluent Manchu in a population of more than 10 million ethnic Manchu living mostly in northeastern China. Manchu is the country's third-largest ethnic group, after Han and Zhuang minority.

The Manchu founded the Qing Dynasty (1644-1911) that ruled China for more than 260 years, but the language was in decline in the 1700s and even the imperial court had lost its fluency by the 19th century. It was China's last dynasty and witnessed China's decline from prosperity.

The Manchu dynasty was known for introducing half-shaved heads and pigtails for men. The fitting high-collared cheongsam, with a side slit, for women is also Manchu in origin.

Shi, who is 35, teaches at the Sanjiazi Manchu School in the northeast province of Heilongjiang where most Manchus live.

Shi's grandmother, 86-year-old Meng Shujing, is one of very few people who can chat fluently in Manchu. She and another 15 old people in the village of Sanjiazi are regarded as "living fossils" of their mother tongue and are paid 200 yuan (US$30) a month by the county to pass on their language. More than 70 percent of the villagers are ethnic Manchu.

Shi, who learned Manchu from his grandmother, was hired in 2006 as a part-time teacher when the village school was set up, with an investment of 2 million yuan. It was the first village school in China teaching Manchu. He became a full-time teacher in 2010 after further language training at Heilongjiang University in the provincial capital Harbin.

Shi now earns more than 1,000 yuan a month and spends his free time managing his family farm.

She and another Manchu teacher have compiled a set of textbooks for five primary grades. First and second graders learn spoken Manchu; from the third grade pupils also learn to read the vertical script. Manchu traditions are explained and displayed in an exhibition room at the school

Remote Sanjiazi village is more than four hours' drive from Harbin; it lies in the middle of a vast paddy field and is encircled by a river. There's one road out of town and there was no modern transport until 20 years ago. In the old days people had to get up before dawn, walk for an hour and a half to the railway station and then take a train to the county seat.

Because of its isolation, Sanjiazi is the only village in China where Manchu language is spoken and its traditions observed, says Dong Xuefeng, an official with Youyi Township, which administers the village.

Liaoning Province was the cradle of Manchu culture, but there is no other village there like Sanjiazi where Manchu is still spoken, says Guan Jialu, an expert in Manchu studies at the Liaoning Academy of Social Sciences.

Prospects for preserving the Manchu tongue are not bright.

Even in Sanjiazi, only a few people can speak, read and write the language, and no more than 20 people across China have a good command of it, says Guan who himself is Manchu. "Manchu is on the verge of demise," Guan says.

Shi's grandmother Meng Shujing says she only uses Manchu with her elderly friends but says they have to add Mandarin Chinese expressions for new words.

Many historical documents in Manchu have not been translated because of a lack of language experts, though the records are valuable in understanding the history of the Qing Dynasty, Guan says.

The documents in the Heilongjiang provincial archive alone can fill six vans but no one can translate them, according to Wu Xuying, director of the ethnic and religious affairs bureau of Fuyu County.

Manchu is a Tungusic language, also known as Manchu-Tungus, and is part of a language family spoken in Eastern Siberia and Manchuria by Tungusic peoples. Drawing on the Mongolian alphabet, vertical Manchu script was created in 1599 by order of Nurhachi (1559-1626), founder of the kingdom of Great Jin, which preceded the Qing Dynasty.

In 1644 the Manchu established a central regime that ruled a territory of more than 13 million square kilometers. It rose after the Ming Dynasty (1368-1644) was toppled by uprisings of peasants.

The Qing Dynasty was at its peak as an empire in the 18th century, witnessing economic boom and unrivaled national strength until Western powers began to flex military muscle in China in the 19th century.

As a result of acculturation with the Han population following their conquest of the hinterland, many Manchu people began to speak Mandarin after they left their place of birth and settled in other parts of the country. They also began to adopt Han surnames.

By the end of the Qing Dynasty, members of the imperial family and Manchu nobles were not using their mother tongue, according to Manchu expert Guan.

Aisin-Gioro Puyi, the last emperor, learned Manchu when he was a child, but later gave it up and forgot it, Guan says.

Long before the collapse of the Qing Dynasty, the Qing court established schools to teach noble descendants their language and culture. At one time it banned the use of Mandarin between Manchus and decreed that Manchus who could not use their mother tongue would not receive official positions.

In 1908, the Qing court established a senior school teaching Manchu in downtown Beijing to preserve the "national quintessence." Similar schools were set up in the northeast.

All these efforts ended after the Revolution of 1911 led by Dr Sun Yat-sen overthrew the Qing Dynasty.

After the People's Republic of China was founded in 1949, the Manchu language received some government attention and study programs were set up.

In addition to Manchu culture research programs, some universities in the northeast such as Heilongjiang University also offer Manchu language courses to the public.

Back in isolated Sanjiazi Village, teacher Shi Junguang has found to his surprise that not all talented students are Manchu. "Some Han kids can speak and read Manchu pretty well," he says.

His expectations are not very high since there is no demand for Manchu.

"But I hope some of them learn enough to pass on their mother tongue so more Manchu descendants understand their culture," he says.