Rosemary Leano, 47, has always juggled two jobs. She has worked for a Harris Teeter grocery store and washed hair at a few beauty shops. She has stocked shelves at KB Toys and Hecht's, sold treats at Cinnabon, answered phones for DirecTV and cleaned houses.

Leano, the daughter of a physician, came to the United States from Bolivia at age 19. She had managed to pay the bills and support her three children but at day's end had little time to pay attention to them. She came to work exhausted and lectured her younger co-workers about the value of education.

"I was telling people, 'You can go to college.' I said, 'You don't want to end up like me,' " Leano recalled. "One day someone at the mall told me, 'You're telling everyone to study, why don't you do it?' "

So 10 months ago, Leano gave up her apartment and began staying with friends so she could afford to enroll in Fairfax County Public Schools' adult education dental assistant program, which cost about $2,000.

Today, Leano -- whose new skills helped her land a job in Vienna -- will graduate with about 150 peers who studied everything from desktop publishing to phlebotomy. The Fairfax school system, the 12th largest in the nation, is known for the programs offered to about 166,000 children and teenagers. But on evenings and weekends, those schools open to adults who come for second chances, better job skills or just to try new things.

School districts across the Washington area offer classes for adults on such diverse topics as French, Easter-egg decorating and art appreciation, but Fairfax's program, with about 43,000 students, is the largest. Last year, nearly 4,000 adults came to receive a high school diploma, and more than 11,000 immigrants took English classes. More than 2,000 people were in apprentice programs that paired them with electricians, plumbers or masons, and hundreds of others took language or cooking classes.

Pat Cole, who has been teaching the dental assistant program for 12 years, said most of her students are immigrants, some who spent years in school in their home countries and others who have only a basic education.

Many are working and have families. Leano said her classmates came from Afghanistan, Somalia, Ethiopia and Tibet.

"Some folks come in and they are just out of high school," Cole said. "Some folks come in and they are grandmothers, and some folks are in-between. They are all different ages and all different academic levels."

Maria Canedo-Toledo, 22, who also will graduate tonight, was studying to become an engineer when her family left Bolivia in 2000 and eventually settled in Virginia. She was 17 then and could have gone to high school, but she worked as a seamstress in a costume shop instead.

"We had to start in new country and find new jobs," she said. "High school goes all day, and I had to work."

Canedo-Toledo went on to work at Panera Bread, but as the family become more settled in their new home, her mother encouraged her to return to school. She started taking classes last year, completing programs in desktop publishing and accounting.

Now she works as a secretary at a landscaping company and has designed advertising brochures and forms used as contracts. She answers phones and helps with the books. "What my boss likes is he asks me, 'Can you do this?' and I say, 'Yes,' " she said.

Bonita M. Moore, director of adult and community education for Fairfax, said many instructors work in their fields by day and teach in the evenings, so students are learning the most up-to-date techniques. The schools also work closely with trade organizations and hospitals and last year began holding job fairs.

Dave Harmon, co-owner of CPS Contractors Inc. in Chantilly, has hired 12 apprentice electricians who are in the Fairfax program. The company pays them $12 to $14 an hour, including the hours they spend in class, and it covers the cost of classes, provided the apprentice earns a passing grade.

Harmon said he would hire someone else from the program on the spot. "If a guy calls me today and says, 'I'm in the apprenticeship program,' I'll say, 'Come and see me,' because they are committed," he said.

Two weeks ago, Leano rented a room in a house in Alexandria. She is saving to get an apartment so her children, who went to live with their father while she took classes, can rejoin her. Her colleagues have started asking whether she will go back to school, perhaps to study to become a dental hygienist.

"I say, why not? It's not too late," she said.

Rosemary Leano, 47, adjusts Edgar Pizarro's braces at the Vienna office of Allen Garai, an orthodontist. She began training to be a dental assistant 10 months ago.