HOOPA, Calif. -- At age 88 and blind in one eye, James Jackson Jr. keeps a crystal clear memory of a tiny linguistic skirmish in a continental campaign that has brought most of North America's Indian languages to the brink of extinction.

"The teacher at the Indian school grabbed my friend by the arm and said, 'You're speaking your language -- I'm going to wash your mouth out with soap,"' Jackson recalled. "That's where we lost it."

Eight decades later, Jackson told his story, in English, to a small circle of Hupa language students. Although the tribe has about 2,000 members, the room contained the four people who make up about half of the world's fluent Hupa speakers: Jackson, his younger sister, Minnie, and two elderly friends. Two others died in February.

Despite five centuries of population decline, assimilation and linguistic oppression, North America's Indian languages have survived surprisingly well: 211 still exist today; there were about 300 such languages when Europeans first arrived in what is now the United States and Canada.

But with the impact of television and radio and increased mobility, North America's Indian languages are suffering their sharpest free fall in recorded history.

Of the 175 Indian languages still spoken in the United States, only 20 are still spoken by mothers to babies, said Michael Krauss, a linguist at the University of Alaska who surveys native languages. In contrast, 70 languages are spoken only by grandparents, and 55 more are spoken by 10 or fewer tribal members.

"This is a major American tragedy that people are generally in a state of denial about," Krauss said. Noting that the federal government spends only $2 million a year to save endangered Indian languages, he said that under the Endangered Species Act, "we are spending $1 million a year per Florida panther to save the species."

Belonging to 62 language families, American Indian languages are as dramatically different as German, Chinese and Turkish.

With the rise of a global economy and increased communications, about half of the world's 6,000 languages are expected to disappear over the next century. Among American Indians, that process is unfolding today.

"We just gave a grant to study Klamath," said Douglas Whalen, a Yale University linguist who directs a new nonprofit group, the Endangered Language Fund. "When the proposal was made, Klamath had two speakers. Now, it is down to one."

Rapid erosion is also affecting the largest tribes.

In Arizona among the Navajo, the most populous tribe in the United States, the portion of native speakers among first-graders has dropped from 90 percent in 1968 to 20 percent today.

In Montana, the 9,300 enrolled Crow members display a classic American Indian linguistic profile: 77 percent of Crow Indians over 66 years of age speak the language, while only 13 percent of preschoolers do. On paper, California has the most linguistic diversity in the nation: 50 Indian languages are still spoken there, down from 80 in the pre-colonial era.

"But not a single one of those languages is now being spoken natively by children," said Leanne Hinton, a linguistics professor at the University of California at Berkeley. "We are heading toward a state where we will have no native speakers of any of the California languages in 10 or 20 years. We are entering an age when speakers of the California languages will be learning in school, or as adults, rather than at home."

As the language circle at the Hupa community center suggests, however, there is a belated movement among American Indians to rescue their languages from extinction.

"It's part of our culture; it contains how a Hupa person views the world -- to lose the language would be to lose our identity," said Daniel Ammon, a Hupa high school teacher who is one of several dozen adults studying the tribe's complex language. "I will talk to my kids all the time in Hupa."

At the regional high school in Hoopa, a town of 1,000 people on a bend of the Trinity River in northwestern California, classes started last fall in the three languages of Indians in this area: Hupa, Karuk and Yurok.

"I want to know Karuk because it is my language, because I want to teach it to my children," Nisha Supahan, 15, said after class as her twin sister, Elaina, giggled in assent.

Their 27-year-old Karuk teacher, Susan Smith, contrasted their attitude with her detribalized upbringing. "I never heard my language as a child," she said. "I didn't even know how to pronounce my tribal name."

Ammon and Ms. Smith learned their native language through an innovative effort to stave off linguistic extinction. Since 1992, the Native California Network, a nonprofit group based in Visalia, in the state's south-central region, has sponsored 50 "apprentices" to undergo intensive language immersions, sometimes for up to 500 hours, with "masters," tribal elders who speak the language.

The language revival effort is taking many forms. Last year the Crow Tribal Council adopted resolutions declaring Crow the official language of the reservation, honoring fluent speakers as "tribal treasures" and encouraging all tribal members to speak the language.

Elsewhere in Montana, the Northern Cheyenne are offering tribal children a summer language camp, taught by the five elders who still speak Cheyenne fluently. In Missoula, summer language classes are offered in Blackfeet. Across Montana, a recent state decision to ease the certification of Indian language instructors has led to an upsurge in language instruction.

Idaho State University now offers Shoshoni for foreign language credit.

"At least one quarter of the 30 tribal colleges now require language study," David Cournoyer, a director of the American Indian College Fund, said in Denver. "Today, 25 different languages are taught, plus Plains Indian sign language."

In Connecticut, the Mohegan and Pequot are studying written records in their languages in an effort to revive languages that have not been spoken since the early 1900s. Due to the work of missionaries and anthropologists, virtually all of the Indian languages in North America have dictionaries and written texts.

While official language extermination policies have stopped, the main threat today, said Krauss, the University of Alaska linguist, is "the cultural nerve gas of television."

Putting electronic communications to work, the Hopi of Arizona have expanded Hopi language radio broadcasting, the Choctaw of Oklahoma have produced native language video dramas, the Sioux of South Dakota maintain a Lakota language internet chat room, and the Skomish of Washington have produced a Twana language CD-ROM.

"There has been an almost total inversion in attitudes toward the native language," said Victor Golla, a linguistics professor at nearby Humboldt State University, who started visiting here 30 years ago. "Before, people were unconcerned about their native language. Now there is a very strong feeling among almost all the people that the loss of their language would be a tragic and very damaging thing."

Indians interested in reviving traditional ways say they cannot pray to their ancestors in English.

"A number of people have learned how to pray in their language," said Ms. Hinton, the Berkeley linguistics professor, who runs a summer program for Indians in California seeking to revive their languages from recorded field notes and tapes. "They are starting to reinvent their languages so they can pray at ceremonies and funerals."

Linguists caution that the language revival movement may only delay inevitable extinctions. But here in Hoopa, a change can already be felt.

"Before, on the bus, I used to say to my sister in Karuk, 'Look at that guy's shirt,' and nobody knew what we were talking about," Nisha Supahan said. "Now that's not true anymore."