Profound changes - some gradual and subtle, others sudden and dramatic - have transformed Arlington from an over-whelmingly white, middle-class suburb into an increasingly urban, cosmopolitan county which has attracted a wide variety of ethnic groups and cultures.

Symbols of that change are everywhere: in stores and restaurants with names like Pacific Oriental Department Store, La Casita and Manila Mart; in a school system where there are 75 foreign languages spoken and a Partent-Teacher Association for Korean parents; in a county health clinic where physicians are treating diseases that have been virtually wiped out in the American-born population but are not uncommon among the foreign-born.

From the forest of concrete and glass towers in Rosslyn, to the wooded expanses of neighborhoods border ing McLean, to the spaghetti-like freeways near Pentagon City and Crystal City, suburb has given way to city.

Once quiet roads now carry tens of thousands of cars a day, and the Metro subway winds through the county. Families - once the backbone of Arlington's population - are being replaced by affluent young singles and professional couples who can afford the high cost of housing.

"When we first moved here this was a rural area," said Phoebe Knipling, a retired teacher who moved to Arlington about 30 years ago when the county had a popluation of approximately 102,000. "We had cows; our neighbors had pigs; very few people locked their doors. There was a small town atmosphere and we were treated like newcomers in a small town."

Today Arlington is scarcely a small town. But despite a history of disquieting changes, said Preston Caruthers, a prominent builder and long-time resident,"Arlington has always been a pleasant place to live. It isn't a Cadillac neighborhood like Bethesda. It's like a Buick or Olds with a lot of Chevrolets."

Caruthers remembers the furor which accompanied the mushrooming developments of homes that sold for roughly $18,000 in the 1950s.

"In those days (we) were condemned for building single-family houses and using up farm-land. Now these houses are like motherhood, they're inviolate," Caruthers lauged. These days, county officials repeatedly cite Arlington's older residential neighborhoods as among the county's greatest strengths.

As the Metro subway has crept up Wilson Boulevard from Rosslyn, so have housing prices in the surrounding neighorhoods. Three-bedroom houses on small lots in Lyon Village, an area close to the future courthouse and Clarendon subway stations, are selling for as much as $150,000, according to county officials. This is a pattern which some residents say is being repeated in the area near the Pentagon City Metro station.

While highly visible changes such as ethnic markets seem confined to certain sections of the county, most notably Clarendon and areas along Columbia Pike, changes in the composition of population have touched schools in all parts of Arlington.

School officals note that between 1975 and 1976 the number of non-English speaking students doubled. Students whose native language is not English make up 19 per cent of the student population.

Four years ago, there was no training for foreign-speaking students in their native language. Today three programs - two federal and one county-originated - are in operation. School officials say they have been been greatly affected by two opposing trends: They have sustained budget cuts in the wake of steadily declining enrollments but they have had to cope with an increasingly diverse student population, which requires additional programs.

School officials say that students whose native language is Spanish, Korean of Vietnamese account for 60 per cent of the foreign-speaking pupils. Other languages represented include Ordu, Farsi and Tagalong (from the Philippines). Many of these students are enrolled in the English for speakers of Other Languages (ESOL) program.

Dr. Marie Shiels-Djouadi, ESOL director, admitted that because of the scope, complexity and novelty of the burgeoning language problems, the school system is sometimes forced to adopt an approach she characterized as "flying by the seat of the pants."

School officials, who are hampered by the difficulty of getting curricular materials in Korean and Vietamese, say they are particularly concerned about the time it takes ESOL students to learn to read and speak English.

"If a child doesn't learn to read with the other kids at the elementary grades there's a real question of when he's going to learn," Djouadi said. Newly arrived high school students present the greatest problems. Officials want them to graduate with their peers but recognize that proficiency in English could take years.

"I am continually amazed by the ability of classroom teachers to accommodate students' needs," Djouadi said. "It's a sophisticated staff, but it's frustrating for a teacher when kids don't seem to be learning."

Officials also predict that the influx of Asian students will increase before it abates. Dr. Todd ENdo, special assistant to school superintendent Larry Cuban, siad he expects a secondary wave of migration to affect Arlington, as Vietnamese refugees move there from other parts of the country.

Mention secondary migration to out-going county human resources director Helen Hackman and she grimaces. "We're really in a much worse position than we were in the late sixties and early seventies when the focus was on preventive measures and innovative programs. Now we struggle just to be able to meet the real crises," she said. Much of the shift, Hackamn siad, is due to budget cuts.

"The new minorities have special health problems like tuberculosis, which is something you almost never see here except in old people. Its incidence is higher among Southeast Asians, who live in such extended families that they may have 17 contacts. For (health workers) one case involving a Vietnamese is much more complicated." Hackman said.

Hackman noted that although many health care pamphlets have been translated into a variety of languages there are no interpreters on the human resources staff. Clinic patients who don't speak English are told to bring an English-speaking friend or relative with them.

Assessment vary of how well the new minorities have adjusted to Arlington.

Red Cross worker Barbara Nnoka is not particularly sanguine about the recent changes. "There's been a lot more changes than even the statistics reveal. Arlretain their own language and ethnic identity . . . and they here who are alienated. They're nonparticipants. They retain their own language and ethnic identity . . . and they are just so tentative that they don't feel they have any rights."

Some black residents, who account for only 6 per cent of Arlington's population, complain that the problems of the new minorities receive more attention than their own. "We have to struggle even harder now," said one woman. "A Vietnamese or Spanish person will get a job much quicker than us."

John Robinson, director of the Martin Luther King Community Centre in the predominatly black section known as Green Valley, agreed. "They're the new 'niggers'," said Robinson of the newly arrived minorities. "They come here and do the jobs blacks used to do, like cafeteria work for $2.30 an hour. Now jobs are scarce and blacks can't even get those jobs."

Robinson said he thought some employers prefer newly arived Asians to blacks. "Often they'll work much harder than (blacks) who've been here all their lives because they're just so glad to be here," he said.

Leaders of the Asian and Hispanicc communities say that their members have experienced discrimination, but they minimize its overall impact.

"It's not so much discrimination, but there's a distance. The larger community doesn't know us," said Nguyen Ngoc Bich, a leader of the Vietnamese community. "I wish (all the ethnic groups) could work together so that there's more acceptance by while society."

The Rev. Frank Park, a social worker and pastor of Arlington's Korean Baptist Church said that learning English and finding housing for large families are among the most serious problems facing Koreans.

Park said that Koreans experience more frequent domestic problems and have significantly hegher divorce rates in this country than they had in Korea. The acute unhappiness of many elderly immigrants concerns both Bich and Park.

"Some are overworked by their families and spend all day cooped up in the house taking care of grandchildren, while their children go to work. They don't learn English and they feel very isolated. Many wish they could go back to Korea," Park said.

To counteract some of the loneliness, Bich recently founded a Vietnamese Senior Citizens' Association whose 100 members meet regularly and take trips together.

Bich noted that many Vietnamese have had an especially hard time dealing with the way they left Vietnam. "Some are still very traumatized by the airlift. Other refugese are quite depressed and some are onsessed by how to get back together with relatives they left behind," Bich siad. "They see their children taking on American ways which is a shock."

Members of the Hispanic community, which predates and outnumbers Arlington's Korean and Vietnamese communities, seem to have adjusted somewhat better. Luis Vidana is chairman of the Committee Hispano, the only minority group organisation which is partially funded by the county board. The committee has been in existence four years.

Vidana, an attorney, said the group was founded because, "we realized the need to keep together or go hungry together." According to Vidana much of the organization's work consists to informing Spanish-speaking residents, 20 per cent of whom are Cuban, about avialable social services. In October the country's Consumer Affairs Office added a Spanish-speaking staff member.

What kind of future do officials and residents envision for Arlington?

Many people - particularly businessmen - are pinning a lot of hope on the impact of Metro. They point to a Council of Governments report issued earlier this year which predicts that Arlington will grow as a commercial center, particularly in the areas surrounding subway stations.

"Metro is going to have a fantastic impact no matter what one thinks of it," said builder Caruthers. "With the coming gas crunch people will attempt. to live and shop using Metro, and (Arlington) took a lion's share of stations and built them very close together."

His assessment, shared by many, is that the new minorities have made a promising initial adjustment and that Arlington's ethnic dieverstiy, close-in location and lowest tax rate of area jurisdictions will become increasingly attractive to potential resients.

Some business leaders and county officials claim that a revitalization of sorts has already begun in Clarendon, which has been targeted for redevelopment as one of Arlington's most depressed commercial areas.

Officials note that the National Graduate University and the National Law School are locating in stores vacated by Kimmei's Furniture and Kann's Department Store. The American Psychological Association recently bought a seven-story office building near the county courthouse and plans to move most of its employees from its downtown location to Clarendon.