By Phil Mercer
BBC News, Sydney
Dharug is firmly embedded in Chifley College's curriculum
The sounds of a lost language echo across a packed classroom in suburban Sydney as high school children help to revive an ancient part of Australia's rich indigenous culture.
Dharug was one of the dominant Aboriginal dialects in the Sydney region when British settlers arrived in 1788, but became extinct under the weight of colonisation.
Details of its demise are sketchy but linguists believe the last of the traditional Dharug speakers died in the late 19th Century, and their unique tongue only survives because of written records.
In a remarkable comeback, Dharug now breathes again - its revitalisation helped by the efforts of staff at Chifley College's Dunheved campus in Sydney.
"We've already reclaimed it. That's why there is so much interest. People are already speaking it," said teacher Richard Green, who, like others, has fought passionately to rejuvenate the ways of his ancestors that were lost after European settlement.
"They weren't allowed to speak it. They had to learn English or they were punished," he added.
When the British ships arrived, there were about 270 different Aboriginal languages in Australia. Today, only about 60 or 70 are spoken on a daily basis.
Of these, roughly half a dozen are considered to be strong and are being passed from adults to their children, according to John Hobson, a lecturer at Sydney University.
"We can regard any language in the world as worth preserving because it has its own unique nature and contains information that we might not be able to express or find in other languages," he told the BBC.
"These are the first languages of Australia. They have suffered incredible attrition at the hands of over 200 years of the invasion of English."
Other indigenous dialects in Australia have been revived but the revitalisation process may require what experts describe as "language engineering" - the borrowing of phrases and words or the coining of new vocabulary for a modern world in ways similar to those undertaken by New Zealand's Maori and the Hawaiians.
"I often compare Aboriginal languages to something somewhere between Japanese and Latin. That surprises people because the gut approach is to go for something primitive and simplistic which they are definitely not.
"They are an item of cultural pride and are very complex languages," said Mr Hobson.
At Chifley College, where around a fifth of the students are Aboriginal, Dharug is taught twice a week with great energy through repetition and song.
"Badagarang!" shouts the class when asked the word for kangaroo. Dingo, wallaby and koala are derived from Dharug.
Hello - warami
Goodbye - yanu
Possum - wubin
Kangaroo - badagarang
White cockatoo - garraway
Relatives (family) - mudyin
Land (countryside) - bembul
Ocean - garragarang
White man - tullamulla
Evil spirit - gubba
The language courses are open to non-indigenous pupils, who now have a greater understanding of their country's rich indigenous history.
For Aboriginal students like Steven Dargin, 16, it is all about identity and pride.
"It's good especially for the black fellas," he said. "You get to talk about your own culture and all that. Learn more stuff and speak it out of school."
His cousin Colleen Dargin, 16, was equally enthusiastic.
"It's all about the Aboriginal language because not many people know it and it's real good that Mr Green is in there teaching us," she said.
Dharug is firmly embedded in the college's curriculum and Joyce Berry, the deputy principal, wants to export the idea to other schools.
"It is a really big journey that we are on," she said. "It would be wonderful if it could go across to other schools as well and that is the aim.
"If this can work, it is something that a school in western Sydney has been able to achieve with the support of the elders," she said.
"If we can do that it's going to be such a wonderful thing not just for the school but for the Dharug community."