For Aracibo Quintana, a bright, bespectacled 6-year-old at Washington's Oyster Elementary School, there are two teachers in his first-grade classroom -- and two languages as well.

One of the teachers, Joanna Leesfield, always speaks to the class in English. The other, Sonia Sagranichiny, always speaks Spanish.

Recently, Leesfield recited, "Peter, Peter Pumpkin Eater" -- in English -- and asked if a pumpkin is a fruit or a vegetable. Aracibo, whose parents are Puerto Rican and speak Spanish at home, told her correctly -- in English -- that a pumpkin is a fruit.

Later, Sagranichiny taught a science lesson -- in Spanish -- about the different ways that animals move. When she asked some questions, Aracibo and his classmates answered enthusiastically in Spanish.

"I decided to send him to Oyster School, said Aracibo's mother, Gianna Rogdriques, "because I wanted him to learn to read and write in Spanish instead of just English . . . In this country you have to learn English to survive, but we want to keep out own culture and language too."

"What we are working for in this school is biliteracy," said Oyster's principal, Frank Miele. "Not one language above the other, but to have and keep both."

Since its program started in 1971, Oyster, at 29th and Calvert streets NW, has been a showplace of the bilingual movement. It has attracted visitors from around the world.

But even though Oyster is hardly typical of bilingual education, its programs, problems and successes are significant because Oyster is one of the nation's oldest fully bilingual public schools.

Its costs are high because the school has two teachers -- one Spanish-speaking and one English-speaking -- in every classroom, with the normal number of students, about 28. As a result, spending per student is approximately double that of other D.C. schools. All the money now comes from local government funds. The substantial federal aid with which the bilingual program was launched stopped five years ago.

"It's caviar," one federal official said. "Nobody could ever expect school systems to afford that. But it shows what bilingual education can do.

Oyster's results have been impressive. Even though about two-thirds of its 325 students are Hispanic and almost 60 percent are poor enough to quality for free lunches, the scores of both its third-grade and sixth-grade pupils averaged six months above the national norms on English-language achievement tests last spring. The students did better in math than in reading, but even their reading scores were above the norm.

However, newcomers who couldn't read English were excluded from the testing. About 14 percent of the school didn't take the tests last year.

Both the teachers and Miele report that the same children generally do poorly or well in most subjects -- whether they are taught in English or Spanish and no matter what their home language may be. Indeed, Miele said the children who pick up the foreign language quickly -- either English or Spanish -- are usually the ones who do well in other subjects.

"The brighter, more motivated children do more in whatever language," Miele said. "And the kids who are struggling along don't seem to achieve too well in anything . . . You know, if you pay attention, you usually do all right. If you don't pay attention, you'll have problems no matter what they're talking up there."

Rosario Gingras, a senior researacher at the Center for Applied Linguistics in Washington, said the same thing has been found in many other bilingual programs: The same children do poorly in both languages.

The result runs counter to the contention of advocates of bilingual education that Mexican-American and many other Hispanic children have done poorly in U.S. schools chiefly because of language problems. "It's very troubling," Gingras said.

Also, contrary to the recommendations of some of the advocates of bilingual education, new students at Oyster -- either Spanish or English -- spend the majority of their time taking intensive instruction in the language they don't already know. Principal Miele said the teachers are native speakers, so that their pupils can pick up a correct accent and idiomatic expressions. But some of the teachers do not speak the child's own language well and virtually all the instruction is in the new language.

"We have to be practical," Miele said. "We're running a bilingual school, and if a child doesn't know the second language, we have to spend more time on the language he doesn't know. You have to be logical about it. Sometimes we might take him out of a history or science lesson (in his native language) to teach him intensive English or Spanish, but then we try to teach some of the vocabulary used in that subject."

Like all District elementary schools, Oyster has a neighborhood attendance zone, most of it covering high-priced areas west of Rock Creek Park and in Kalorama. But Miele said that about half of the students come from outside the zone with special permission, because their English is limited.

Most of these students live in the Adams-Morgan area or Mount Pleasant, east of Rock Creek Park. The schools there are virtually all black, in contrast to Oyster, whose enrollment is about 12 percent black and whose neighborhood children mostly are white.

Some of the out-of-zone children said their parents sent them to Oyster because it doesn't have as much fighting as their neighborhood schools, and not just because of its language program. Although in some cities black groups have conplained that bilingual programs for Hispanics have served as an "out" from desegration, in Washington the transfer of Hispanic children from black neighborhood schools to Oyster has stirred little controversy.

It has brought some quiet criticism from whites who live near Oyster that the school has become "dominated" by Spanish. Although enrollment in the bilingual program originally was supposed to be about half English-speakers and half Spanish, those from Spanish homes now outnumber the others by 2 to 1. From 1976 to this fall the number of non-Hispanic whites attending Oyster dropped from 113 to 65.

Miele and some of Oyster's teachers said they think the drop in neighborhood whites was caused by soaring real estate prices and restrictions on children in apartments and condominiums. But several white parents who switched their children to other schools say that their youngsters sometimes felt like outsiders at what they termed "La Oyster," or found Spanish to be a burden. And a few parents said their children had not been challenged enough in basic subjects.

However, white parents whose children remain at Oyster seem enthusiastic.

"We feel very fortunate," said Elise Merrow, a former president of the PTA. "Our experience has been that the language never is a problem. The kids really do have a healthier respect for other cultures and their own. And they've learned a great deal. I can't say enough for (the school) -- except that it costs a lot."