More than 1,000 people crowded into the Ontario Theater on Columbia Road NW Thursday night to inaugurate the return of English-language films to the theater, which was for the past eight years the only Spanish-language movie house in Washington.

The crowd that showed up, mostly young white artists, journalists and professionals, was amazed at its own numbers.

"They're coming out of the woodwork," one said.

Well-wishers, greeted Paul S. Tauber and Herbert White, the Onatario's new co-owners, in the plant-filled lobby of the 26-year old theater at 1700 Columbia Rd. with "Congratulations," "It's amazing," and kisses, hugs and hope for the success of the theater.

"I'm exhausted," said Tauber, 41, collapsing into a chair once the movie, "Watermelon Man," a 1970 release, began.

Tauber, who in 1974 opened the popular neighborhood bar and restaurant Columbia Station three blocks away, and White, a friend and real estate developer, bought the Ontario from the KB Theater chain last week for $400,-000.

According to Tauber, KB decided to sell in part because the 1,000-seat "Teatro Ontario" was losing money featuring Spanish-language films, Marvin Goldman, a KB Theaters representative, yesterday denied the Ontario had been losing money. He added that KB plans to open a new all-Spanish movie house in either Northern Virginia or the Takoma Park area. "We're following the migratory patterns of the Spanish, who are moving out to more affluent neighborhoods," he said.

"There is no Spanish community here anymore," Tauber said. "The films they were showing were 20 years old. The Spanish people are-not losing a theater."

The switch to English-language films at the Ontario is an illustration of how much the Adams-Morgan neighborhood, where it is located, has changed in the past few years.

In recent years, Adams-Morgan has been considered the most culturally diverse neighborhood in the city, a mixture of Spanish-speaking, blacks and whites: old and spacious apartments and low-priced ethnic restaurants.

But young whites, attracted by the neighborhood's cultural mix, have been moving into the neighborhood recently. Their arrival is considered by some as a threat to the diversity that attracted them there in the first place.

Some merchants and residents who do not welcome the changes are fighting what they call the "Georgetownization" of Admas-Morgan.

Thursday night the scene did have a touch of liberal chic. During the screening, the party was going strong as the crowd spilled over into the aisles, lounging on the carpeted stairs, drinking wine and munching free popcorn.

Upstairs in the Ontario's two glass-enclosed balcony rooms joints were freely passed as guests relaxed in the rocking chair seats.

Downstairs, Joe Laskin, owner of Cosmo Liquors on Columbia Road, said he welcomes the changes in the neighborhood.

"I've lived here for 35 years," Laskin said. "I saw this theater go up brick-by-brick. I've stayed when others left. I saw this trend coming years ago, and I've been saying all along this will be another Georgetown. I love it."

"This is the greatest thing to happen to this neighborhood," said Ronni Wing, who lives on Ontario Road NW.

Winslow Peck, editor of "Counterspy" magazine, says he has mixed emotions. "I think the theater is reflecting a reality in the neighborhood, but it's sad for the Spanish community. I would hope that the new owners would be responsible to all elements in the neighborhood, not just us white folks."

Tauber and White do not consider the changes in Adams-Morgan to be "Georgetownization."

"This isn't Georgetown," White said.

"We're just local people. I've owned property here since 1965. I've lived through the riots when no one would touch it. It's not Georgetown, but it's the closest thing to New York we have."

Tabuer said no one in the Spanish community has contacted him about the loss of Spanish films, and he has received nothing but support from the neighborhood.

It's a neigborhood coming together," he said. "I love this place, I own property here. I think it's the greatest neighborhood in Washington. and 1977 is the right time for the Ontario."

When the movie ended a local rock band. "The Look," played while patrons literally danced in the aisles.

Some partygoers admired the perfect condition of the theater.

"I saw 'Lawrence of Arabia' here," one woman said.

"No, it was 'Sound of Music," her companion argued.

Outside the snow had started to fall and two young girls hesitated at the theater doors.

"Is this an opening?" one of them called in.

"Sure," someone answered, and invited the pair inside. Still not convinced they asked:

"Is it for the Neigborhood?" TSeveral people standing n the lobby responded in unison, "yes."

The two girls walked in slapped each other's palms and said "Allright."