Mr. Grant estimates that thousands of students have read the books and taken courses on the language, first through informal workshops held in the nation’s capital, Canberra, from the early 1990s. In December 2015, at a branch of Charles Sturt University in Wagga Wagga, New South Wales, students completed the first-ever course in Wiradjuri.
To a great extent, Mr. Grant is carrying out a promise to his beloved grandfather, who singled him out as a youngster as his heir to Wiradjuri culture.
“My grandfather was a Wiradjuri elder,” he said, and was anxious to pass along the culture. “But he was arrested after he called to me in Wiradjuri to come home from the park. ‘Barray yanha, barray yanha,’ ‘Come quickly,’ he called out.”
Mr. Grant was probably 8 or 9 years old the night a local policeman heard his grandfather, Wilfred Johnson, and locked him up. But he does not recall a sense of alarm.
“He was an elegant man,” he said of Mr. Johnson. “He was beautifully dressed, usually in a coat and hat. But he was black. So it wasn’t the first time he had spent the night in jail.”
After the arrest, Mr. Johnson, who spoke seven languages, refused to speak Wiradjuri in public.
“He was a linguist with enormous respect for his own people and culture,” said Mr. Grant, who speaks three languages himself: Italian, which he picked up while working at the sawmill, as well as English and Wiradjuri. “But he told me, ‘Things are different now.’ He would only speak his language in the bush.”
It was during those expeditions into the backcountry that Mr. Grant learned Wiradjuri, as well as tracking and hunting skills. He knows that a echidna’s back feet turn inward, complicating tracking. He can describe how his grandfather made a lasso out of long grass to catch a stunned goanna, a type of lizard, for dinner, and he says a rope laid around a bush house will stop snakes from passing over the threshold.
Lloyd Dolan, a Wiradjuri lecturer who has worked with Mr. Grant, said elders took risks teaching Wiradjuri to their children. Mr. Dolan also learned Wiradjuri from his grandfather. His mother forbade him to speak it at home.
“There was a real fear that the children would be taken away if authorities heard kids speaking the language,” Mr. Dolan, 49, said from his office at Charles Sturt University. “The drive to assimilate Aboriginals into white society was systemic.”
Aboriginal people had no right to vote in elections before 1962, and they were counted as wildlife until a change to Australia’s Constitution in 1967.
Mr. Grant grew up in poverty, his family drifting from place to place: Redfern, a rough-and-tumble Sydney suburb; Griffith, a village 60 miles northwest of Narrandera, where he lives now, and Wagga Wagga, which is 62 miles southeast of that.
He recalls vividly moving from a “humpy,” a dirt-floored makeshift shack, consisting of just a few rooms, on the fringe of a country town, into a house with electricity. “It was the first time we had electricity at home, but it wasn’t on much because we had no money to pay for it,” he said with a laugh.
As a child, Mr. Grant said, he scorned his grandfather’s ways. He was embarrassed to be black. By the time he was 17, in 1957, his grandfather had died, and he had dropped out of school, left home and found a job on the railways.
Soon, he moved from a small town to Sydney, where he says he drank a lot, got a tattoo of a roughly drawn dagger and eventually found himself in jail.
“I cried and cried when that happened,” he said. “I had been drinking and probably brawling, and I didn’t want to be there.”
It was his wife, Betty, now 73, who helped turn his life around. After marrying in August 1962, they spent several weeks living out of a shell of a car on the Aboriginal Three Ways Mission on the fringe of Griffith, in central New South Wales.
Mr. Grant soon found a job at a sawmill, and although an accident mangled two fingers of his left hand, it was steady work. He and his wife started a family.
Around that time, Aboriginal activists began agitating for civil rights. In 1965, Charles Perkins, the first Aboriginal to attend the University of Sydney, led 35 student protesters on a Freedom Ride bus tour around outback country towns. They were pelted with gravel and harassed as they went from small town to small town, where they called for an end to segregated seating on buses and in theaters. They demanded equal service in shops and hotels, and they wanted Aboriginal children admitted to municipal swimming pools with white children.
Six years later, Neville Bonner, a leader from an Aboriginal rights organization, became the first Aboriginal to gain a seat in Australia’s Parliament, filling a Senate vacancy left by a Queenslander who had resigned.
With the help of these small civic changes, Mr. Grant, whose formal education ended at age 15, managed to navigate a way forward for himself and his family. He first found work in Canberra helping Aboriginal children who had skipped school.
Around the same time, there was a push to document Aboriginal culture and language, which was rarely written down. As one of the few who knew Wiradjuri language, he was approached about writing it down. That eventually led him to teaching his language and writing “A New Wiradjuri Dictionary,” published in 2005.
“I was told when you revive a lost language, you give it back to all mankind,” he said, sitting in his kitchen, not far from where the kingfishers darted across the Murrumbidgee.
“We were a nothing people for a long time. And it is a big movement now, learning Wiradjuri. I’ve done all that work. I’ve done all I can.”