THERE IS NO BLACKBOARD jungle in Alex Costea's schoolhouse. No one-way staircase to readily explain the stress. The daily tensions, which hunch the shoulders of this high school English teacher, are not so dramatic. But they sometimes churn his stomach none the less.

"Right now I need a hammer and a wedge to start pounding on something," jokes Costea to the first of his five classes at Arlington's Washington-Lee High School after a 12th grader has asked a 4th grade question. "You'd think some of this stuff would have rubbed off."

Behold the conscientious teacher. After 28 years in the "education game," after 40 zillion imcomplete sentences, misplaced commas and mangled verbs, Alex Costea, Doctor of Education, still teaches with enthusiasm. Successes, however small, are celebarted. But failures are also mourned. And the sum of those, he acknowledges, coupled with the sad economic reality of his profession, have taken their toil on the doctor.

"Sometimes the chore really becomes a chore," says the 53-year-old Costea, who has outlasted Our Miss Brooks and Mr. Novak, but may not survive the White Shadow. "I'd like to retire as soon as I possibly can."

It would be inaccuarte to label Costea a "teacher burnout." He has served his time in education. He wants to retire "before I have to move right into a rocking chair." But Costea does exhibit some of the symptoms of the condition which education journals across the country warn is approaching epidemic proportions.

Runaway inflation has compressed the noraml grind of high workloads and low pay to squeeze some of the best teachers, and administrators, from the profession. Many of those who remain are working second and even third jobs to maintain old standards of living.

"Teachers get on a treadmill; they don't get enough sleep; they become less efficient in their teaching, and they start to feel guilty about it," says Gerry Gripper, president of the Fairfax Education Association, who estimates that at least 20 percent of his association's 6,500 teachers are working jobs outside of school. "More and more, teachers are dropping out, copping out or opting out because they're burned out."

Teachers have also become more militant in response to the economic squeeze. Within the last year teachers in Virginia's Fairfax, Arlington, Loudoun and Prince William Counties have staged job actions, refusing to participate in extracurricular activities or to take work home with them. Montgomery County teachers threatened to strike earlier this year before a new two-year contract was agreed upon. And District teachers did go on strike, for a month last spring.

There is enough employe frustration in little red school houses across the nation to make a kindergarten teacher curse.

In Arlington, where the job action continues, some teachers complain that county politics has also increased the pressure they work under. Walter Frankland, chairman of the county board and its Republican majority, this year accused the Arlington school board, which has a Democratic majority, of leading the school system into a decline. Many teachers felt the criticism was a slap at their professionalism.

"I don't think it's valid to say we've somehow gone downhill," says Costea. "Politically it's neat to say that. It implies politicans have the banner to lead us back up the hill. But then that's the politicans' stock in trade. What else do they have on their shelves?"

Costea, the son of a bus driver and father of six children, has held a variety of jobs in the Arlington school system. In 1954 after emigrating from Cleveland where he taught for two years, Costea spent six years as an elementary school science teacher. He then graduated to an administration job, supervising elementary science education. In 1969, after 10 years as a boss, Costea decided to "get back in the game" by teaching English at Washington-Lee.

"I've always respected Alex for that decision," says Mary Bullock, a 14-year veteran English teacher at Washington-Lee. "Any self-respecting teacher knows this is where the real work is going on."

During his stint in administration, Costea also hosted a half-hour television show, "Time For Science," which was broadcast by Channel 26 to classrooms throughout the metropolitan area. The show, which was watched by 50,000 elementary school students at its peak in 1961, featured Costea as a local Mr. Wizard.

"I never won any Emmy for that thing, but I was the matinee idol of the fourth grade," says Costea, his blue eyes dancing above black glasses perched near the tip of his nose. "Of course you have to remember some of those kids were a captive audience. About 49,993 of them."

Costea uses his sense of humor, whichis sharp enough to cut but rarely does, as a teaching tool. It also helps to maintain his perspective as year follows imperfect year.

"At the end of every school year, the teachers, the students and the administrators breathe a sigh of relief and get away from here as fast as they can. We all know we made mistakes, but we say wait until next year. Things will be different," says Costea between bites of a ham sandwich lunch at his desk.

"It's the old Brooklyn Dodger Syndrome. The only darn reason the Brooklyn Dodgers aren't losing today is because there aren't any Brooklyn Dodgers."

Costea teaches 110 students in five classes at Washington-Lee. Two of those classes are made up of 10th grade "modified" students. Translated into English, that means they are slow learners. The 80 students in his three 12th grade classes are "regular" students. By the 12th grade, the brightest students have already been culled out for advanced classes.

"They are kind of the nitty gritty," says Bullock. "And he gets them to do it. It's very impressive."

Costea realizes he will be the last English teacher for many of his students. He doesn't tell anecdotes in class. He teaches the course -- Shakespeare, essay writing, research papers and, more often then he would like, spelling and simple punctuation.

Costea does not expect all of his students to be prepared. Sigh. But if he isn't, the anxiety twists his stomach and hunces his shoulders up to his earlobes.

"Maybe it's just me, but I feel like I should know what the heck I'm doing. It throws kids off when they detect I'm not prepared. If I'm not confident all my ducks are in a row, I can be pretty uptight."

By his own admission, Costea is "hyper." Even without the demands he makes on himself, which colleagues say go "above and beyond professional concern," Costea says the act of teaching is an inevitable strain.

"Day after day, hour by hour, standing up there trying to control kids, their relationship with me and each other, and still teach them is a draining experience."

Costea battles his tension with early morning swims, stress management courses and an annual weekend retreat at a Trappist monastery in Berryville, Va. -- stopgap methods all.

But he cannot afford to plug that drain by quitting. Two of his children are still living at home. His house, a modest brick rambler in a residential neighborhood near Fairfax County's Seven Corners, is not paid for. After 26 years in Arlington he is only making $30,000 a year. If he waits another seven years to retire, he will earn roughly 65 percent of that income annually. But if he retires before then, for every year under 60 he will lose another 4 1/2 percent of that annual amount.

"It's not a good retirment plan," says Costea evenly. "Anybody who thinks a little bit says why the heck did you stay? That's a good question. I don't have a good answer to that."

Later, Costea will think of answers. Students who come back to thank him. And oh yes, there are the perks that come with teaching.

"We have an executive bathroom just like Johnny Carson's," winks Costea, fumbling for the key to a closet-sized room with one toilet. "He's not so smart."