LAST JULY A LANGUAGE TEACHER named Zalmai Zahir performed an audacious experiment, with himself as the guinea pig. He had been contracted by the Squaxin Island Tribe to ride with its members for two weeks on the annual Tribal Canoe Journey, when nearly a hundred traditional canoes from scores of tribes cross the region’s inland waters. Zahir would do some paddling on the long haul from the southwest tip of Puget Sound to the remote Makah reservation, home of this year’s hosts. His unique role: to instruct other paddlers in the language of his heart—Lushootseed, the original language of the peoples that dwelt all around the Sound.

Though we give that language no thought, we all live with it—in the names that surround us, tongue-twisting even in anglicized, bastardized form: Snoqualmie, Snohomish, Skokomish, Skykomish, Swinomish, Stillaguamish, Suquamish, Duwamish, Puyallup, Tulalip, Mukilteo, Muckleshoot, Skagit. Every day we butcher the name of the chief formerly known as siʔaɫ (pronounced “see-oth,” more or less), who’s famously said to have prophesied that “the streets of your cities [will] throng with the returning hosts that once filled and still love this beautiful land.”

If the spirits of Chief siʔaɫ‘s people don’t get back soon, they may not find anyone to talk to. A few years ago Lushootseed, once spoken along every shore and stream from the Skagit Valley in the north to Skookum Inlet in the south, reached the end of its natural life. Not a single primary speaker—someone who grew up speaking Lushootseed as a first language—survived; even the elders who learned it (imperfectly) as children from their parents and grandparents grew up speaking primarily English. It looked like one more speck of linguistic roadkill on the highway of globalization, one of the 3,000 languages (out of about 6,900 still spoken worldwide) expected to vanish before this century ends.

Desperate times call for desperate measures. Zahir decided to take the dare that an academic colleague had posed, half facetiously, never expecting he’d try it: Rather than offering the sort of classes he’d conducted for years with the Squaxins and other tribes, he would speak, read, and as much as possible think only in Lushootseed. “Could I do it?” he wondered. How would it affect him and the people around him, many of whom knew no Lushootseed and none of whom were fully fluent in it? Would they avoid him or try to respond? Would he grow frustrated and weary, or more proficient? “Could I express complex ideas?” he asked himself. “Would I feel the need to resort to English in extreme situations?”

Using red yarn, Zahir tied an index card laminated in packaging tape around his neck. “ʔutxʷəlšucidəbəxʷ čəd,” it read. “I SPEAK LUSHOOTSEED. . . . Please accept my apologies in advance for not speaking English.” A few people shunned him, but most embraced his experiment; children were the most receptive, and the best at repeating his Lushootseed phrases. He found he could communicate what he needed to (with the aid of gestures, at which he is as expressive and uninhibited as any mime) with everyone he met—even in stores and restaurants along the way.

Those who knew any Lushootseed at all put it to use. “A few surprised me, for they previously spoke very little or no Lushootseed at all,” Zahir wrote in an account of the trip posted (along with the journal he kept in Lushootseed) on his site, pugetsalish.com. One friend who’d claimed not to know much Lushootseed pitched in as interpreter, translating what he said into English. Zahir was especially gratified to discover that his example prompted people from faraway tribes to speak in their languages. “One woman told me in Athabascan she was Tlingit [from Alaska], but then told me she lived on the Zuni reservation and began to speak Zuni.”

As he neared the end of his two-week vow Zahir found it harder to stay in linguistic character; he strained for words (even his Lushootseed vocabulary is far from complete) and his thoughts drifted into English. But his experiment was a milestone. He had spent longer living in Lushootseed than anyone had in decades.

Though Zahir himself would modestly refuse the honor, he may be the most fluent Lushootseed speaker now alive. And, as his name suggests, he did not come to his cultural patrimony merely through an accident of birth.