It’s a typical morning at a typical mountain resort — with one difference.

Here at the Berkshire Hills Emanuel Adult Vacation Center near Albany, N.Y., it’s Yiddish Vokh, or Yiddish Week. Every activity, from morning calisthenics to volleyball to roasting marshmallows under the stars, takes place entirely in the mame-loshn, or mother tongue.

Every August, Yiddish-lovers head for these spacious lakeside lawns with one goal in mind: to spend seven days in Yiddish land. The event’s 29th season, which ended Tuesday, drew more than 150 participants from New York, Baltimore, Washington, Los Angeles, Boston, New Jersey, Chicago, Philadelphia, St. Louis and Denver — as well as Australia, Brazil, Canada and Israel.

At the registration desk, participants collected packets containing pages and pages of sports and leisure terms in Yiddish. Then they put on their Yiddish nametags: Mike became Motl, Jeffrey turned into Itsik-Leyb, Cecile became Tsirl and Peggy was now Chaye.

For most Jews today, the 1,000-year-old Germanic tongue written in Hebrew letters has all but vanished from daily life. But at Yiddish Vokh, America’s only weeklong all-Yiddish retreat, it’s everywhere.

Little children play katchke, katchke, ganz — duck, duck, goose — on the lawn, while their older siblings compete in a scavenger hunt. Elderly couples shmooze in lawn chairs under the trees, and a dozen women perform vigorous shpringendike yankelekh, or jumping jacks, in the pool.

Rowboats glide on the glassy surface of the lake, and the hilke-pilke field fills up with klappers (batters), khappers (catchers) and feldnikes (fielders) playing softball.

Meanwhile, inside the red clapboard buildings, native speakers offer classes to help the grine, or greenhorns, with vocabulary, reading and writing. There’s a writers’ group and a leyenkrayz, or reading circle, origami and calligraphy, a discussion of God and a presentation on how to preserve family archives.

The activities go on late into the night. One evening featured the work of the classic Yiddish writer I.L. Peretz, followed by a shrek-mayse, or ghost story, with the lights turned off. On another evening, participants acted out a raunchy parody of “Saturday Night Live.”

The New York Jewish People’s Philharmonic Chorus sang, and there were films and a klezmer band. On the last night, a homegrown talent show was a shlagger, or big hit.

Ben “Binyumen” Schaechter, a 41-year-old pianist and composer, has directed Yiddish Vokh since 1993. The son of a renowned Yiddish linguist, he grew up in a Yiddish-speaking enclave in the Bronx. He and his three sisters have raised their children in Yiddish.

For Schaechter, Yiddish Vokh is no sentimental trip back to the Old World.

“Yiddish for me is not about the past,” Schaechter told JTA — in Yiddish, of course. “I live it every day.”

Schaechter carefully screens new applicants by phone, stressing that the retreat is designed only for those committed to the real thing — all Yiddish, all the time.

“I actively discourage some people from coming,” he said.

For those neophytes, he recommends other Yiddish activities — classes, trips to the Yiddish theater and cultural programs such as Klezkamp or KlezKanada.

For some, the retreat is a mekhaye, a pleasure.

Myra Mniewski, 51, grew up speaking Yiddish at home with her parents, who were refugees from Hitler’s Europe. Now she directs Yiddish Vokh’s parent organization, Yugntruf, or “Call to Youth” (www.yugntruf.org), and speaks Yiddish at home with her partner.

“It’s the language itself that draws me,” she said. “Here I pick up idiomatic expressions that I can take home and use in daily life.”

For those still striving to master the language, the week can be a struggle.

Joan “Taybl” Levin’s parents and grandparents spoke Yiddish when they didn’t want her to understand.

“Yiddish was all about secrets,” she said.

This was her second year at Yiddish Vokh.

“It’s very hard for me,” she said. “Every conversation is a challenge. But I manage.”

Retreat leaders devote considerable energy to updating Yiddish, coining new words that bubbe never knew from. Cell phones — which don’t actually function on the Yiddish Vokh campus — are mobilkes or tselkes. Basketball is netsbol, e-mail is blitz-post and flip-flops are finger-shikh, or toe-shoes.

Hanging on to the language of the shtetl, much less trying to drag it into the 21st century, may seem hopeless or silly to some. But for Yiddish Vokh-niks, it’s a dead-serious matter.

“Hitler and Stalin wiped out the old Jewish communities,” said Mark “Meyer” David, a computer programmer from Boston who hosts “The Yiddish Voice” radio program.

“Only the language is left,” he said. “Yiddish puts me in touch with an exterminated culture.”

Before the Holocaust, 11 million people spoke Yiddish. Today it’s estimated that between 500,000 and 2 million people use the language, notably in fervently Orthodox communities — although the language enjoyed a mini-revival among younger, less observant Jews during the 1990s.

Anne “Kahane” Eakin Moss, 32, is not observant, but said Yiddish gives her and her family a secular connection to Jewish identity.

Moss and her husband speak only Yiddish with their son Isaac, age two. They come to Yiddish Vokh every year in order to meet other families with Yiddish-speaking children.

Some of Moss’ friends warned that being raised in a Yiddish-speaking home in English-speaking Baltimore would confuse Isaac, but Moss felt just the opposite: Bilingualism is good for the brain, she believes.

“He’s ahead of many kids his age,” she says.

Isaac’s grandparents supported the decision to raise him in Yiddish, with one exception.

“They didn’t want to be called ‘bubbe’ and ‘zeyde,’ ” Moss said. “It sounded too old to them.”

Eventually they relented.

Many of Yiddish Vokh’s teenagers have been regulars since infancy and consider it a high point of their year.

“We grew up here,” said Judith “Yudis” Waletzky, 18, a sophomore at Northeastern University in Boston. “It’s a second home for us.”

Waletzky and her friends do their nails together in Yiddish, pelt each other with water balloons in Yiddish and stay up late singing Yiddish songs at the top of their lungs. Their motto is an invented hybrid word: vusever (for “whatever”).

This year, participants of all ages were snapping up “VUSEVER” T-shirts on sale in the dining hall.

If Yiddish is fun for these teens, it’s also a passionate cause.

“Yiddish is an incredibly important gift,” Waletzky says. “Our parents spent decades building this community. Now it’s our responsibility to carry it forward into the future.”

Waletzky plans to raise her own children in Yiddish someday, and so does her Yiddish Vokh friend Shifra Whiteman, a 17-year-old New Yorker. When people tell Shifra that Yiddish is dead, she has a ready answer:

“Do I look dead to you?” she asks. “Yiddish lebt,” or Yiddish lives.