"Wholesale" return of pupils to school after February half term is "unlikely", Wales' first minister has said.
Mark Drakeford said there were "intermediate positions between where we are today, with very few children in school, and everybody being back".
Previously, ministers said schools would stay closed to most until February half term unless Covid cases fell significantly.
Those preparing for qualifications and very young children may return first.
Mr Drakeford told a coronavirus briefing on Friday he had recently chaired a meeting of the teaching unions and local education authorities.
"We all agreed that we would work purposefully together to find ways of bringing more young people back into the classroom," he said.
"Does that mean that we will see a wholesale return of every child in every classroom, every day of the week across Wales? I do think that that is probably unlikely.
"But there are intermediate positions between where we are today, with very few children in school, and everybody being back."
He said there had been "practical, creative, imaginative" proposals put forward which could mean some children being back in the classroom for some of the week.
These could include "children preparing for qualifications [and] very young children for whom online learning really isn't a genuine possibility".
"I certainly don't rule out making some of those things happen after the February half term, but I do think it's unlikely in the way you said that we would see every child back full-time in every classroom in the way that we would ideally wish to do," he added.
All schools and colleges moved to online learning before Christmas, following concerns from unions over the new coronavirus variant.
They have remained open for children of critical workers and vulnerable learners, as well as for learners who needed to complete essential exams or assessments.
'Orderly return to school'
Earlier this month, when Education Minister Kirsty Williams said schools and colleges would stay closed to most pupils until the February half term, unions welcomed the news, saying the health and safety of pupils and staff "had to be a priority".
But, they added, teachers must now be given the vaccine as a priority, and pupils and staff must be protected before talks about reopening schools could begin.
Teachers are still not on the priority list for immunisation, and have to wait to get the jab dependent on their age and if they have a medical condition.
At the time, Laura Doel, director of The National Association of Headteachers Cymru, said: "Any plan that sees school staff return to face-to-face learning should be afforded as much protection as possible against the virus.
"Once these issues have been addressed, then we can discuss the orderly return to school we all want."
Opposition parties have called for clear plans on how schools would return and for support to make sure pupils from poorer backgrounds did not fall behind due to a "digital divide".
Plaid Cymru's education spokeswoman Sian Gwenllian said: "The Welsh Government must plan now for the gradual and safe reopening of schools, putting in place safety measures, and should lay out plans for a vaccination programme for schools staff."
Welsh Conservative education spokeswoman Suzy Davies called for the Welsh Government to publish evidence on its reasons for closing schools, bring forward vaccines for teachers, and said money must be made available for all pupils to access laptops for online learning.