He passes for an African American teenager, easily. The talk, the poise, the posture, even the cornrows. He is dressed in the trademark style of the urban teen: Baggy jeans, Timberland boots, Versace sunglasses, baseball cap. At 17, Jose Mendoza is visibly and inescapably black. He brings up Martin Luther King Jr. and Rosa Parks, race and its tribulations. "Why do white people gotta hate black people?" he asked. "Know what I'm sayin?' "

He once played a joke at George Washington High School, home to upper Manhattan's immigrants since the early 1920s. Fluent in English and fluent in "street," Mendoza fooled everyone by pretending he was a bona fide American black. But this American-born, Spanish-speaking Dominican was simply too good. Some Dominicans, not keen on African Americans, thought he was too African, too American, too black.

One day he surprised two Dominican girls derisively talking about him in Spanish. "Que fue lo que tu dijiste?" he asked. "What did you say?" His Spanish made him suddenly Dominican. From then on, he said recently, "they treated me with respect."

This is Mendoza's world, the complex and conflicted world of black Latinos. He is at once very black but not quite black enough for many African Americans, very Latino but not light enough to matter to most Hispanics, American in every way but at the same time inexorably foreign. "From the inside we're Dominicans. From the outside, we're black," is how he described it.

Dominicans account for eight in every 10 students at George Washington, reflecting the enormous migration of islanders to New York City. Dominicans have been the largest immigrant group in the city every decade since 1970, and this historic influx has altered the face of the immigrant population here and introduced an entirely new culture. To assimilate, or even to fit in, the black Latinos must adapt not only to white America and black America but to Latino America.

Their strong ties to the island make them citizens of both countries and, it seems, citizens of neither. "They are here and there and in between. Yet they are perceived as foreigners in both locations," noted Luis E. Guarnizo, a sociologist at the University of California at Davis and an authority on the Dominican migration.

Nowhere is the assimilation of black Latinos more evident than in New York, where Dominicans have flocked in such great numbers. Throughout the early 1990s, the Dominican Republic accounted for one in five immigrants to the city, an average of 22,000 annually, according to the most current figures. By next year, the Dominican population in New York City may reach 700,000, the equivalent of many middle-sized cities.

Between 1990 and 1994, an astonishing 35,657 Dominicans settled in Washington Heights, Inwood and Hamilton Heights, contiguous neighborhoods in upper Manhattan that have been dramatically altered by the legal migration from the Caribbean. Dominicans, skillful at grass-roots organization, already are a force on the New York school board and have elected two judges, a city councilman and a state assemblyman. Politically they have fit in better and faster than most immigrant groups. New York City Council member Guillermo Linares, the country's first elected official born in the Dominican Republic, said Dominicans like to refer to themselves as "300 percenters--100 percent Dominican Republic, 100 percent Dominican American and 100 percent American."

But on the street and in school, what is skin deep is often what matters. While those with Mendoza's skin color will be automatically identified as black, many lighter-skinned Dominicans are not so easily pegged. In his writings, the Dominican writer Junot Diaz uses the term "halfie" to describe this significant group. One consequence is that many in the community define themselves less by color than by cultural identity. "Where you gravitate to speaks so loudly," Linares said, reflecting the unusual position many Dominicans are in because so many can literally choose their race.

Of course, black Dominicans like Mendoza don't have that choice. And while his comfortable identification with African Americans shows he has answered a central question faced by Dominicans--black like who?--hundreds of thousands must still reconcile their very nuanced views on race with the stark black-white reality of their adopted country.

Finding a place for themselves, much less assimilating, has not been easy. Afro-Latinos are largely ignored by leaders of African American national groups. "We have to go there and give them evidence that we are black, which doesn't mean they will believe us," Silvio Torres-Saillant, the director of the Dominican Studies Center at the City College of New York, said of African American civil rights groups.

Diaz, whose short fiction has been lauded for capturing the varied landscape of the Dominican diaspora, said America's dialogue between blacks and whites is so narrow that it leaves out this large and new migration. African Americans "are allowed to be black because they don't speak Spanish," he said, "but I'm not allowed to be black because I speak Spanish."

Afro-Latinos are ignored even by some fellow Latinos. And when they're not, they are often depicted in ways no longer tolerated by African Americans. While national Hispanic groups bitterly complain about how they are portrayed in the English-speaking media, a small group of Afro-Latinos has fought, largely in vain, to remove stereotyping in the Spanish-language media. Roland Roebuck, an Afro-Latino from Puerto Rico, last year wrote a bitter letter about the portrayal of black Latinos to Henry Cisneros, a former Clinton administration Cabinet member and now president of the powerful Univision network.

"Imagine for a moment, Mr. Cisneros, how an Afro-Latino family viewing your station feels when our people are portrayed in your news, novelas and programs as criminal, savage, lazy, slick, sex-driven, violent, superstitious, uneducated, undependable and untrustworthy," wrote Roebuck, who works for the District government.

If Afro-Latinos are sometimes ignored by their own kind, they are practically invisible in America. The black Latino, so visible on the streets of upper Manhattan and especially in major league baseball, still does not register in the collective American definition of who a Hispanic is.

As if this were not challenge enough, Dominican migrants must also reconcile their island's complex racial code with America's historically contentious one. In the Dominican Republic, the oppressors have generally been mulattoes and light-skinned blacks. One of the worst insults for a black Dominican is to call him a Haitian. Haiti invaded and occupied the Dominican Republic twice and these seminal events heavily influence the island's view on race. "You are what you appear to be," said Torres-Saillant, "which is very different from the generic racial definition here."

Which is, in essence, what happened to Mendoza when he pulled off his joke. Dominican students, seeing his black skin, "dissed" him because he was black and seemingly foreign to them. The African American he pretended to be became the hated Haitian of the island. In a group of light- and brown-skinned students and teachers, the island's racial sensibilities hold sway. Parents' preference is for sons and daughters to marry "light," according to some teenagers.

For Dominicans, particularly teenagers, sorting out their racial identity can be confusing. Teenagers choose their race, going white or black, depending on their own skin tone. "Some of the kids who are darker more readily accept the African Americans, and they look to that kind of music," said Thomas Garcia, a Dominican who teaches at the school.

"You see that black guy? He's Dominican," Albert Bonilla, 17, said one day between classes, when the hallways were crowded. The student Bonilla singled out, like Bonilla himself, was a light-skinned black who was "thugged out," their term for hip-hop getup that defines the group.

"My grandmother be like, put your pants up! Subate el pantalon!" said Bonilla. "You see the way we talk?" he asked. "You don't hear white people talking like that."

Mendoza and other black Dominicans identify with African American culture--their game, for example, is basketball and not baseball. They talk in what is best described as "black spanglish," a mix of English and Spanish with a decidedly hip-hop accent.

"I used to be a decent boy," Mendoza said, cracking up the kids around him. Now, he said, he filters race through the African American experience. "If white people are going to hate me," he said, "I'm going to hate back."

Mendoza fulfills the prediction of one study that said the longer black Dominicans are in this country the likelier they are to identify with American blacks. But after all his talk and posturing, Mendoza steps back just a little and, like Linares, plays the percent game. He announces that he still prefers rice and beans over American food. He calls it "a Dominican plate. The grub."

"I'm still part Dominican," he said, suddenly serious. "That's my nationality. If you become African American, you give your nationality away. That's like saying you're betraying your country."

CAPTION: Dominican students Jose Mendoza and Albert Bonilla talk at New York's George Washington High School. In background is Jenny Guzman. Many face dilemma in identification.

CAPTION: Dominicans, who account for eight out of every 10 students at George Washington High School in upper Manhattan, must adapt to black, white and Latino worlds.

CAPTION: Jenny Guzman, 16, a Dominican high schooler in Washington Heights.