SAN FRANCISCO -- When she first emigrated, and walked through Chinatown's streets speaking Mandarin, people muttered under their breath. They called Rose Pak a Chinese person who didn't speak Chinese.

As she walks through the same neighborhood three decades later, the scene is decidedly different. Pak points to a store bedecked with brightly colored kites, and another serving won ton and chow mein -- both Mandarin-speaking, she says. A Mandarin pop singer belts out a love song over a sidewalk speaker, and a man greets Pak with "Ni hao," -- Mandarin for 'Hello.'

A gradual shift from Cantonese, a dialect spoken in southern China, to China's official language of Mandarin, has been taking place in America's Chinese communities. These days, Mandarin's growing influence can be heard even in San Francisco's Chinatown, long a bastion of Cantonese speakers.

"Now, nobody pays attention because it's so common," said Pak, a longtime Chinatown activist and consultant for the Chinese Chamber of Commerce, who speaks both languages. Though Cantonese remains Chinatown's primary tongue, many shopkeepers speak at least a few words of Mandarin, or "they try to, anyway."

Statistics document the shifting landscape: a 1986 consumer survey found almost 70 percent of Chinese households in the San Francisco area spoke Cantonese; 19 percent spoke Mandarin. A survey last year showed the divide narrowing to 53 percent Cantonese and 47 percent Mandarin, according to a study for KTSF, a television station that devotes most of its programming to Asian-language shows.

The trend is similar in Los Angeles and New York, the nation's two other major Chinese markets, said Saul Gitlin of Kang & Lee Advertising in New York.

"Ten or 15 years ago, Mandarin would have been very, very small," Gitlin said.

The linguistic changes tell the story of Chinese in America. In the mid-19th century, tens of thousands of Cantonese fled economic and political turmoil in southern China's Pearl River Delta area, following the lure of the Gold Rush. Over the next few decades, several Chinatowns sprang up across the nation, said Chinese-American historian Him Mark Lai.

The Immigration Act of 1965 lifted national origins quotas, ushering in a second wave of immigrants from Hong Kong, where mostly Cantonese is spoken and Taiwan, where Mandarin is more common.

Many people in this second wave were students or professionals who started technology companies during the Internet boom and settled in suburbs like Fremont, Milpitas and Cupertino in northern California. Just east of downtown Los Angeles, the suburb of Monterey Park was dubbed "Little Taipei," after Taiwan's capital.

In more recent years, the number of mainland, Mandarin-speaking Chinese immigrants has surged. In 2002, 61,000 people arrived from mainland China -- about 10 times the number of those from Hong Kong, and six times the amount of Taiwanese, according to federal statistics.

"What is driving the 'Mandarinization' of the Chinese-American community is the very strong influx of immigrants from the People's Republic of China," Gitlin said.

Now, signs of Mandarin's growing acceptance are everywhere. Members of Chinatown's venerable Cantonese family associations have taken to warbling Mandarin pop songs at banquets, accompanied by karaoke machines, and showing off their Mandarin in speeches before Chinese government officials, Pak said.

Last year, the Chinese Newcomers Service Center in Chinatown began offering workshops in both Mandarin and Cantonese, instead of just Cantonese, said program coordinator Jamie Woo.

Mandarin also is filtering into more homes through music and movies. And though the written Chinese language can be read by both Mandarin and Cantonese speakers, Chinese-language newspaper Sing Tao Daily has been trying to weed out Cantonese slang from its reports to appeal to more Mandarin speakers, said Tim Lau, vice president of the paper's western edition.

Greg Sullivan, president of Asian Marketing & Media Services in Los Angeles, predicts the shift toward Mandarin will continue, and eventually, "you're going to end up pretty much with markets that are even up."

While some may lump Cantonese and Mandarin speakers into one group, there are some distinct cultural differences, observers say.

"Because the only group of people for at least 100 years that American Europeans have been in contact with are the Cantonese, they assumed that the food and cultural things they witnessed ... in the Chinese community were absolutely what China was about," said Pamela Wei, a San Francisco filmmaker who has produced documentaries about China's culture.

But "it's a huge country," Wei said. "When we talk about Europe, we don't talk about European cuisine. We talk about Italian, Greek."

At Kin Fai Produce in Chinatown, mainland Chinese make up about 30 percent of Lisa Tham's clientele. Tham said she appreciates all her customers but mainland Chinese "are more price conscious and quality conscious" and many try to bargain with her.

Power structures also vary, said Kathay Feng, an attorney at the Asian Pacific American Legal Center in Los Angeles.

"In Chinatown, many times the gatekeepers are people who belong to family associations," Feng said. But for newer, Mandarin-speaking immigrants involved in churches, weekend Chinese schools or musical organizations, "it's very different, much more diverse and not as easy to identify a handful of community leaders."

Some say Cantonese and Mandarin speakers tend to stick to their own groups, which are defined by language as well as class.

"The social circles are still very sharp," said Lai, a San Francisco-born Cantonese speaker. "I don't have very many people that I know that are Taiwanese, for instance, or Fujianese."

Wei, who was born in Australia and spent 10 years in China, identifies with her Manchurian grandmother's roots. "I'm always looking for northern people in the Bay Area," Wei said.

"I've been brought up with them, the language. It's a certain feeling that doesn't exist between myself and the Cantonese. It's like a shared experience of place and food and the way of doing things."

Despite those differences, New York City engineer Leo Lee said Mandarin is emerging as a common language, providing a connection between the diverse Chinese communities. "There are more and more people that would consider Mandarin to be the least common denominator," he said.