There aren't many Americans left in the building in Arlington where 18-year-old Mai Anh lives. There were more, but that was before the fall of Saigon, before the rise of condominium conversions, and before the events that have made Mai Anh's world in Northern Virginia not so unlike the one she left in Vietnam more than a year ago.

Since her arrival, Mai Anh has been exposed to foreign ways. But more often than not, those ways are not American. Although she speaks English with a friend who lives in the next building, it's because it is the only language the two teen-aged girls -- one Vietnamese-Chinese, the other Laotian -- have in common.

Hue, too, had to make adjustments when she and her family moved into the apartment above Mai Anh. Hue also came from Saigon, but unlike Mai Anh, she spoke only Chinese when she came to America. To get along with neighbors and classmates, she learned Vietnamese as well as English.

Such cultural interminglings -- rare in Asia -- have become a way of life in Park Warren Towers, a triangle of mid-rise apartment buildings on the outer fringes of Arlington that in recent years has become home to several hundred of the Washington area's large and growing Asian refugee population.

No one can say for sure how many Southeast Asians live in Park Warren's 198 units. Census data taken last year show more than 400 Asians out of 1,010 residents in the area near the apartments, but the numbers fluctuate.

County officials say that the concentration of refugees at Park Warren is among the highest in Arlington, a county that has felt proportionately the second largest impact of refugee migration in the country, after San Francisco.

The daily scenes at Park Warren tell more than the numbers. In the afternoons, the upper parking lot by two of the complex's three buildings is alive with children, playing marbles or jumping rope in a barren, sandy patch between the cars. Their shrieks are in a babble of languages; their faces are Oriental and their feet, in spite of the autumn chill, are clad only in rubber-thonged sandals.

Inside, around supper time, the corridors fill with the smells of incense and Asian cooking -- pickled fish, vegetables cooking in oil at high heat, pungent sauces. After dark, the children move their marble games onto the dingy hallways, dodging adults on their way home from school or work.

In the laundry rooms, in the elevators and in the lobbies, English has become a rarity as the refugee families carry on their daily lives in an environment that, but for the modern appliances, more and more resembles their native lands. Oriental plants, sprouting squash-like vegetables, grow on back porches. Even the Safeway, at the bottom of the hill in the Columbia Pike Shopping Center, has begun stocking tree-ear mushrooms, tiger lily buds, miniature shrimp and large bags of rice.

For reasons as old as their cultures and as new as the pressures of Arlington's housing squeeze, Asian families at Park Warren -- as elsewhere -- have piled into the apartments, sometimes as many as 13 in three-bedroom units and six in one-bedroom apartments. The crowding is, for some, an economic necessity to pay a $565 rent for three bedrooms, $480 for two bedrooms. It is also a product of large, extended families of overlapping kinship -- grandmothers, sisters-in-law, sometimes cousins or even friends from villages back home.

Park Warren has not been strict about crowding -- to the dismay of some of its dwindling number of American residents. "When we came out here, they had rules," said one tenant of 10 years who plans to move out when her lease is up. "No more."

Crowding -- rarely barred by the county -- compounds a cultural clash that has gradually driven many American residents out. For the Americans, as for the Asians, the language barrier is a frustrating obstacle. People who once enjoyed hallway chats with neighbors now feel isolated. When children of an upstairs tenant make too much noise or drop things down on the porch below, there is no easy avenue for complaints.

So when some Americans began to suspect that neighborhood pets were disappearing, possibly to be eaten by the foreigners, the inability to communicate only heightened the real or imagined fears. One tenant, who asked not to be named, is missing two of her five cats. She has no proof of any wrongdoing but now, she says, she won't let her pets outside. "I can't enjoy it anymore," she said, "I just want to go somewhere where the cats can walk around without my being worried to death."

Daniel Rothenhoefer has heard the rumors about stolen pets. He has made a point of getting to know many of his foreign neighbors at 840 S. Dickerson but he can think of no one he can approach about the pet question -- even though some say the problem has the potential of souring the relative harmony in his building.

Rothenhoefer always has relished the international atmosphere at Park Warren. When he moved in in the late 1960s, there was a sizable foreign community, primarily of employes from the Indian, Pakistani, Afghan and Libyan embassies as well as Cuban refugees. He left and returned again in 1977, in time to witness the steady arrival of Southeast Asian refugees.

Park Warren proved to be a natural magnet for the refugees. Although rents are high, the management's liberal policies made it a haven, particularly for families evicted by stricter landlords. Furthermore, Park Warren, perched on a hill overlooking Columbia Pike, is near schools and the bus to the county's language and job training center.

While maintenance at Park Warren has been a problem for years, the Asian tenants are less complaining than their American predecessors, according to county inspectors. Inspectors used to be swamped with calls as soon as the heating or air-conditioning systems broke down; now, they say, the complaints are down to a trickle, even though the 20-year-old red and green brick buildings are clearly showing signs of age -- missing panes of glass, peeling wallpaper, erratic elevators and uncollected trash.

As Park Warren was discovered by more refugees and their sponsors, relatives tended to congregate around each other, threading family ties through the brick buildings. Mai Anh's sister-in-law and her child already lived at Park Warren when the rest of the family moved in. In the last month her sister-in-law's parents have joined the compound, so when her sister-in-law, a seamstress, is at work, she has two sets of grandparents available.

When Phung Quoc Hung, his brother and his brother's family came to live in a one-bedroom apartment at 5110 S. 8th Rd., there were, he says, only a few Vietnamese families in Park Warren Towers. Since then, relatives have moved into an apartment upstairs and his brother, after a month in San Francisco, moved back to Arlington into another Park Warren apartment, this time down the hill at 840 S. Dickerson St.

The interweaving of families has led to a certain homogeneity among the tenants. According to residents, many, possibly most, of the refugees are -- like Mai Anh's and Hue's families -- ethnic Chinese from Saigon, a group that fled Vietnam in great numbers after the fall of the South Vietnamese government.

There are few Laotians and Cambodians. One Laotian resident, who has lived there a year, said she knows only two other families from her country. Of the handful of Cambodians there, at least two families moved in only in the last two months.

Families remain the strongest bond, as they were in Asia. When she isn't studying, Mai Anh helps her mother, a diabetic, with cooking and shopping. There is little time for visiting, except a two-hour bus ride twice a month to see an aunt in Silver Spring. Besides, for her as for most refugees, the struggle to adapt, to survive is all-consuming. "People have to go to work or they have to study," said Phung Duoc Hung, "There's no time."

But there are other ties, sometimes coincidental. Hue discovered a family she had met at the Bibon refugee camp in Malaysia living downstairs on the first floor. Visouthone's mother, Nom, a widow who is supporting her four children by working in a downtown Washington bank, was surprised to learn that the father of a Laotian family also living at Park Warren Towers had once worked for her late husband in Vientiane.

Nom Viphongsanarath, fluent in English from her years working for the U.S Embassy and the U.N. in Laos and at the Nongkai camp in Thailand, has tried to bridge the cultural gap with other nationalities. When a large Cambodian family moved in across the hall, she wrote out -- in French -- directions for calling police, fire and rescue. And when her sponsor comes by with food for her family, she shares it with either the Cambodians or the Vietnamese next door. "We are only five," she said simply, "and they are so many."

But the gap can be frustrating. "It's so hard for them when they have an emergency. I want to help but I can't speak," she says.

Naturally, friendships and liaisons are easiest among people of the same background and age. Hue, Mai Anh and other Vietnamese-Chinese friends go together and pay $4 to watch six hours of Chinese movies at a Rosslyn theatre. For the older generation, there are other links, such as the Chinese language newspapers, published in New York, which Hue's and Mai Anh's fathers trade.

Religion, too, enforces cultural differences. Cambodians and Laotians are almost all Buddhists while many Vietnamese, including some Vietnamese-Chinese, are Catholic. And the Buddhists, according to their national origins, go to different temples -- the Cambodians to New Carrolton in Maryland, the Laotians to Springfield and the Vietnamese to 16th Street in Washington or to Falls Church. The differences also show up at home. In a Chinese Buddhist apartment, the corner by the dinner table is reserved for sacred figures, framed by Christmas tree lights. Lao households keep wooden carvings of the Buddhist monument at Thatluang.

But under the pressures of a new life and a strange land, cultural and language barriers are beginning to crumble, particularly among the younger generation. The children who play in the parking lot are oblivious of origins. Hue's mother goes grocery shopping with a Vietnamese neighbor. And Mai Anh and Visouthone, who met walking to Wakefield High School together, are now best of friends, in spite of the differences in their background -- Mai Anh the 18-year-old daughter of a Chinese acupuncturist and Visouthone, the 17-year-old daughter of a governor of Vientiane who died in a Communist "re-education camp" in 1977.

It is comforting to many that life in America has succeeded in smoothing over centuries of differences, even antagonisms. "Since we leave my country, since we live here, I think Vietnamese and Chinese get very friendly," explained Mai Anh earnestly. And her friend Visouthone happily described the dishes she has learned to cook in Mai Anh's kitchen -- which, she discovered, were not so different from her own Laotian foods.

But if a new-found truce exists among the various Southeast Asian cultures, it has become increasingly elusive between Asians and Americans. There, the cultural gap is, for some, just too wide, too mystifying, to be bridged by the occasional silent nod and smile. For some Buddhists, exterminating cockroaches is taboo; for American neighbors, such religious beliefs defy modern sanitary standards.

The message of the Americans' gradual departure from Park Warren is not lost on some of its newer residents. "I think they don't like to make friends with us," said Hue simply.