A few hundred black students trickled back to Soweto's segregated schools yesterday but thousands continued their boycott as the government reopened schools in hopes of ending the five-month-old student strike.

Twelve of the 40 high schools in the black ghetto of Johannesburg opened but education officials said they will not know until next week how many of Soweto's 27,000 secondary students will abandon their protest over inferior education for blacks.

Students face pressure to onctinue their boycott from the newly formed militant Soweto Students' League. According to one report, members of this clandestine group burned hundreds of application forms at once school.

The openings were limited to a dozen schools in an effort to prevent violence and there were no reports to incidents or arrests.

Many blacks feel that the white-minority government will never listen to their demands to scrap the Bantu education program, the separate and unequal system of schooling for 4 million black youths in South Africa.

The changes the government has made, like dropping the word "Bantu" have not met black students' demands for fundamental modifications in the system. Such is the mistrust and suspicion of the government among blacks that the promise this week by Prime Minister John Vorster that "changes and improvements" will be made is not believed.

The boycott has created a generation of students who are increasingly bitter toward the government. "The government will never again see moderate blacks - this generation is too bitter," said one 30-year-old social worker.

With the banning of the once powerful Soweto Student's Representative Council last October and the jailing of many of its leaders, the students' unity has been wrecked and they are now subjected to conflicting pressures.

One of the students who returned to school said that he and his friends did so because "the boycott was not doing anything." The student als said they were influenced by Zulu Chief Gatsha Buthelezi, who urged pupils to return in a speech last Sunday in Soweto.

Most of Soweto's secondary students already have missed two years of schooling because of sporadic riots and boycotts since June 1976. As a result, many students have been sent by their parents to boarding schools in Swaziland, Botswana or rural areas of South Africa, despite warnings from militants that this would be regarded as a betrayal of the students' cause.

Many other students have fled the country or are in jail, but the vast majority roam the streets with nothing to do, facing the prospect of perhaps never obtaining their high school diploma.

"We are idle," one student replied when asked what he did all day.

Most students had hoped to find part-time jobs. But jobs are scarce and when students do find an opening, employers often do not want to hire them.

"Industry is not keen to employ someone who left school after the riots," said one social worker who did not wish to be named. "They fear they will be hiring a militant who will foment troubles among the workers later on."

Many parents say they have lost control over their children. "I have no sons anymore, said Williem Nkosi. "I have two lodgers who come to me for food and beds and when I tell them to go back to school they laugh and threaten me. They tell me they are soldiers in a war and I must not be a traitor."

Other parents, however, have supported their children's boycott effort. One social worker said: "Our children have the courage to stand up and sya 'no' to a system of education that we too did not want to accept, but were to timid to oppose."

But these parents say they go off to work worried that their unsupervised teen-agers will get into trouble. There has been an increase in adolescent pregnancies and in the use of (marijuana), Soweto social workers say.

The Soweto students who have led the "children's revolution" over the past 20 months cince the riots of June 1976 shook South Africa want education because it is their only ticket ot a decent job and economic security. But they were dissatisfied with the inferior education they were getting and decided "to see if starvation for two or three years was not better than half a loaf," one Soweto teacher said. Many of the teachers have joined the boycott.

Last week the government announced it was making the Department of Black Education into a separate ministry and changing its name, but the Blacks feel that this is just window dressing.

"The people won't be satisfied with anything less than a clear declaration of intent to narrow the gap between spending on white education and spending on black education," said Hamilton Dlamlenze, secretary general of the African Teachers Association of South Africa.