John Ross speaks Cherokee. He is one of several thousand fluent speakers of this indigenous North American language, the native tongue of generations born more than 50 years ago.“My parents, grandparents, they could hardly speak English,” says Ross, age 58, a translation specialist for the Cherokee Nation in Tahlequah, Oklahoma. “Really, there was no need to learn any other language aside from Cherokee.” But that changed when government-run schools forced Cherokee out of the classroom, leading to a break in language transmission from Ross’s generation to the next and setting the stage for extinction.Today, the Cherokee language is actually in far better shape than most indigenous languages around the world. Some languages have only one speaker left, such as Siletz Dee-ni, the last of 27 native languages spoken on the Siletz Reservation in Oregon. By the end of this century, almost half of the planet’s approximately 7,000 languages could vanish; many are spoken by small tribes that have no written traditions.Language extinction is as old as language. Societal changes and colonization …