Philimon had not seen his mother and father for four years when he arrived in this country from Ethiopia two years ago. He was 9 years old then, a nervous boy with downcast eyes and a timid smile. His parents had come to the United States to work, leaving him and his brother and sisters in Ethiopia with his paternal grandmother, who lived on a small farm.

Philimon remembers taking the sheep to graze and walking two miles to school every day. He said he flunked first grade, but recalls little else about his education in his homeland.

Rosa was 10 when she came here from El Salvador. When she was just 1 year old, her mother left her with an aunt in a small town near San Salvador and came to the United States to work as a housekeeper. Every month, she sent Rosa money for food and clothes. She also visited Rosa every few years.

Because of the guerrilla war in her country, the one-room school Rosa attended was frequently closed, until finally, when Rosa was about 7, it closed for good. "The teacher was killed," said Rosa matter-of-factly. After that, Rosa did not receive any schooling.

When Rosa and Philimon began attending classes at Rolling Terrace Elementary School in Silver Spring they had few of the basic skills most American children their age have acquired.

Philimon did not know how to hold a pencil. On the first day he attended school, he sat down at a table, pulled several toys from his pockets and began to play with them, one teacher said.

Rosa was quiet and withdrawn. She did not know how to read or write and could not count beyond 10.

Today, both children can read and write, and add and subtract.

Every year more and more illiterate refugee children are attending school in Montgomery County and other Washington area jurisdictions, school officials say. Many come from Southeast Asia or Central America.

For many such children, war or political turmoil in their countries has interrupted their education. Some come from cultures where writing does not exist. Many, like Rosa and Philimon, have been separated from their parents for long periods of time, a situation that makes learning more difficult, teachers said.

The number of foreign-born youngsters enrolled in English as a Second Language (ESOL) classes in Montgomery County has almost doubled in the past seven years, from 2,100 in 1978 to 4,046 this year, said Maria Schaub, director of the school system's ESOL program. They come from 90 countries and speak 60 languages.

Schaub said 332 of the children enrolled in ESOL classes in Montgomery County this year have had little or no previous schooling.

In Prince George's County, about 300 of the 1,800 children enrolled in ESOL classes lack basic reading and writing skills, said Lillian Falk, coordinator of ESOL for the county school system.

"With some of these children we are starting at a level of teaching them to hold a pencil and that you read from left to right," Falk said. She said some children from parts of Laos and Cambodia have never been exposed to written language. "They come from a culture that did not have a written tradition but an oral one."

ESOL teachers agree that teaching such children poses a difficult challenge. A foreign-born child with basic skills can usually learn enough English in several years to be transferred into a regular class with English-speaking students. But a child who lacks basic skills will have to spend at least two extra years in ESOL just to catch up, instructors said.

"We try to give them a feeling that just because it takes them a little longer, that doesn't mean they are failing," Falk said.

Schools in Prince George's County do not have special basic skills classes for refugee children, Falk said, although the ESOL program includes a special curriculum for illiterate children.

In Montgomery County, there are special basic skills classes at the junior high and high school levels in math and language skills for students who lack prior schooling.

The classes are smaller, usually about 12 to 16 students, and more intensive. At the end of last year, 80 refugee students were learning basic skills at five junior high or intermediate schools, Schaub said.

She said that although there is a need for a similar basic skills program at the elementary school level, none now exists. Instead, illiterate refugee children are taught in the regular ESOL classes.

"The ESOL program is not for them because they have almost no basic skills," Schaub said. She said she plans to ask the school administration to budget money next year to establish a basic skills program at the elementary school level.

But many of the learning problems these children confront cannot be resolved simply through smaller classes and more contact with their teachers, officials said. Some have other stresses in their lives that may make it more difficult to teach them basic skills, teachers said.

Those who have been separated from their parents for long periods of time may be having problems adjusting to their families. "When the child is finally reunited with the mother, there may be many conflicting feelings," said Vilma Montiel, the counselor in the Montgomery County ESOL program.

"There is a great deal of resentment on the part of the youngster and a fair share of guilt on the part of the mother."

Montiel said family turmoil often is manifested in behavior problems in school. Many of the children, she said, do not pay attention in class, have temper tantrums, fight with other children and are unpredictable and explosive.

When Rosa came to live with her mother at age 10, she reacted negatively to a 4-year-old sister who had been born in this country. "She would tell me she wanted nothing to do with her little sister," said Rosa's mother, Juana Barahona. "She would say that she wasn't her sister." Slowly, Rosa has begun accepting her sibling, her mother said. "It's much better now."

Philimon was a special challange to his teachers. He was separated from his parents from the time he was 5 until he was 9 years old. An uncle tried to help him, his brother and sister escape from Ethiopia to Sudan, but they were caught and imprisoned by soldiers, from whom they fled only to return home, Philimon said

His parents then paid a friend to lead the children out of Ethiopia. They walked for a month, only at night for fear of being detected, surviving on wheat and coffee. The children then stayed in Sudan for a year until they were able to fly to Germany and then to the United States where they were reunited with their parents.

At the airport in Washington, Philimon said he reacted to his mother as a stranger after so many years. "I said, 'Who is this lady?' " the boy recalled recently as he sat in a classroom at Rolling Terrace, nervously fidgeting with a green pencil.

When Philimon began attending school he would hit and scratch other children and would get into fights on the school bus, said Jo Ellen Tannenbaum, his ESOL teacher. "The entire first year he was here he walked around with a frown on his face," Tannenbaum recalled.

Philimon smiles now, an easy, happy-go-lucky smile. And he can read; his favorite book in the school library is one about dinosaurs.

Rosa is reading, too. She prefers a book called "On the Rock in the Pond" and can read it alone in halting but understandable English. "I am so proud of her," Tannenbaum said. "She has learned beautifully."

Educators speak with surprise and some pride of such accomplishments among children like Rosa and Philimon who come to their classes from harsh lives elsewhere. In spite of the hardships, the heartaches and the trauma, the children learn, Falk said. "They show a tremendous resiliency."