Chicago Public Schools officials knew some kids would be taught by instructors still working from home when 50,000 preschool through eighth grade students returned to classrooms earlier this year.

On April 19, that number is expected to increase to more than 95,000 pre-K through eighth grade students. And while CPS officials are promising more teachers in school, it’s still possible that some classrooms will still be led by teachers working remotely. In those cases, students will watch their teacher online with an adult supervisor, most of whom are not certified to teach.

At the high school level, where students regularly change classrooms every period, about 26,000 students are expected to show up for in-person learning on April 19. CPS is still negotiating with the Chicago Teachers Union on the return of high school teachers.

How often have kids been in classrooms with virtual teachers? More than one in five teachers were initially allowed to continue working remotely through CPS-approved accommodations, according to a WBEZ analysis of CPS data. A small number also took unpaid leaves. In 70 of 400 schools, more than 40% of the teachers were not in buildings.

“I’m confident that we will have employees back to work,” said CPS’ Chief Talent Officer Matt Lyons, whose office is reviewing the accommodations to consider which are still necessary.

However, the school district has so far only confirmed that about 20% of the 6,600 pre-K through 8th grade staff on leave or working from home will be back.

Which teachers must return to school remains the focal point of a reopening debate that pits the needs of struggling students against the concerns of staff who want to protect themselves and their families against the virus. Meanwhile, parents are concerned that students without in-person teachers have too much down time, and some said it’s not even worth bringing their kids to school. Some principals fear they will be blamed for the quality of in-person education.

Rachel Gigliotti, whose eighth grade daughter reports in-person twice a week to Jackson Magnet Academy on the Near West Side, said none of the eighth grade teachers are physically there.

Overall, Gigliotti said, her daughter seems happier with a new routine and being around other kids — even if they are still sitting in front of a computer. Yet, Gigliotti said she’s concerned that her daughter and other students are left without instruction for more than an hour per day.

“If they’ve finished their homework, there’s really nothing for them to do,” she said. “And the adult that’s monitoring the class doesn’t really engage with them. So I think when the teachers are there, they may end up having other ways to inspire the kids or to create some engagement.”

Lyons acknowledged staffing difficulties since students returned in February and March. However, Lyons said the overall situation isn’t as dire as it may seem because some of the teachers still working from home also have no in-person students. Others are gym or music teachers, he said.

Troy LaRaviere, the head of the Chicago Principals and Administrators Association, said school leaders will need significantly more staff in the buildings when more students return. Currently, he said, many schools are so short-staffed that principals “dread” if even one staff member scheduled to work the building calls in sick.

“The only reason that things are not breaking down is because so few students showed up to this school,” LaRaviere said. “So if indeed, more students show up, we’re going to have even more trouble than we have now.”

He said principals are worried parents will blame them for the lack of quality in-person education.

For the initial reopening, the school district hired hundreds of extra temporary staff and substitute teachers to help with elementary schools and preschools. Officials have not said whether they will do the same for high schools.

CTU President Jesse Sharkey said the debate over accommodations in high schools often centers on teacher concerns about students being put in unsafe environments. High school students have been shown to transmit the virus more and, though those 16 and older with underlying conditions can be vaccinated, few have.

“We have a lot of members who have a lot of doubts about whether it’s wise to be running back into a high school setting, ” Sharkey said.

Sharkey said most fully vaccinated teachers will be ready to return in person, but some people won’t get vaccinated for a variety of reasons — from being pregnant to being nervous about vaccinations.

Also, some teachers who have children at home may be worried about exposing their sons or daughters, who can not yet be vaccinated.

Lyons said part of the reason he doesn’t know exactly how many staff will be back in schools is that the union has told staff they don’t have to disclose whether they have been vaccinated. Only 41% of staff responded to a school district survey on vaccinations.

He said the school district is hamstrung by this lack of information and can’t tell parents and principals exactly which teachers will be back.

Sharkey, though, dismissed the idea that withholding information is a potential problem in getting teachers and staff to return on April 19. He said staff are worried that they will have their accommodations or leaves pulled immediately if they reveal they are fully vaccinated. He said they want to stay at home until April 19, but most understand they will be expected back at that time.