As American parents and students begin to consider what school will look like in the fall, children across much of the world have returned to schools already, finding them barely recognizable, with new layouts and routines adapted for the coronavirus pandemic.

Cafeterias look like exam halls with desks spaced out, temperatures are checked, shared computers are unplugged, and there are no sports. For some, yellow signs on the ground dictate which directions they should walk, with paths divided by ages. For others, school has been reduced to a few hours a day or takes place only on alternating days.

The measures are deemed necessary to reopen schools that gradually closed through the first few months of the year as the outbreak spread from China. Three students—from elementary to high schools—in different countries spoke to The Wall Street Journal about how they are adjusting to the changes.

After four months of doing lessons via Zoom calls at his kitchen table with his mom, 10-year-old Rhys Jones was eager to see his classmates again when his school, ESF Kennedy School, an international elementary school, reopened at the end of May.

“He can’t wait to stop home schooling and be able to play with his friends,” his mother, Jennifer Jones, said the day before he went back. He had told her how he planned to show them a new toy he had just been given—a “snowball crunch” stress ball—and listed a long list of boys he planned to hang out with on his first day back.

School didn’t turn out to be quite as fun as he expected.

The 900-student school is trying to keep the students several feet apart at all times. Lunch—previously eaten in classrooms—is now eaten in the school’s hall in shifts. Chairs are set out in a grid exactly one meter, or a little more than 3 feet, apart and the children must bring a packed lunch. Utensils are banned.

After lunch, he can play in one of the school’s three playgrounds but he has to stay where he is once he has made a choice and can’t wander between them as students used to. He said that means he gets separated from his friends if they don’t know which playground to meet in.

All sports involving a ball, including soccer and rugby, have been banned. The school has stopped students from playing in a big field at lunchtime. There is no sports equipment. Teachers wander the grounds reminding the students to stay more than 3 feet apart.

“I miss the games because we can’t play half of them. You can’t play football or tag,” said Rhys, who attends school on alternate weekdays. He said instead they have played other games, including one called Bulldogs where they run across a court without being caught by another student, or he sits at a distance from his friends and just talks to them. Board games in the classroom, which children often played during lunch when it rained, have been removed, which makes wet-weather lunches boring, said his schoolmate Bella Chappell.

Besides the irritation of wearing his mask all day, his class has been split into two rooms and the teacher divides her time between them. Some of his friends are now in other classes and he has to wait for breaks to see them.

Every day at lunch, he has a friend sitting about 3 feet away, so they can still chat. Even with all the changes, he said he would rather be in school than learning from home every day.

“I get to see my friends—some of them I haven’t seen for more than three months,” he said.

New Zealand came close to eradicating the coronavirus after the government imposed one of the strictest lockdowns globally, yet returning to school is still optional for Jess.

Her school’s shift toward using technology and online tools means that children can attend the same classes at home or in school.

Bream Bay College, which teaches middle- and high-school students, has replaced the school’s white boards with flat-screen TVs that mirror teachers’ tablets and all the classes are webcast live, allowing children to follow along from home.

Still, only around 10% of the 520 students aged 11 to 18 have remained at home. Jess said this means that there is always one or two children logging into class from home with their images shown on screen at the front of the class.

“In P.E. we are doing workouts with three people and one of our group is still at home, so what we did was call him and he did it on the device,” Jess said.

Jess’s mother, Selina Gordon, said she gave her children the choice of not going back. “But they were ready. They missed their friends.”

In New Zealand schools, masks are optional—and few are wearing them—but there is hand sanitizer at every classroom door and for use when getting on and off the bus. Students are required to use antiseptic spray to wipe down their own desks and sports equipment. Class computers have been unplugged. Bean bags have been removed and there are plastic boards that can be erected between children where children sit close together.

Assemblies are beamed to the TV screens while the students are in the homeroom or watching from home.

While Jess was excited to be back, her mother found it bittersweet.

“How often do you get to lock your teenagers up at home for a month? And have them have to talk to you?” Ms. Gordon said.

Song Eun-jo, a 17-year-old senior at Daewon Foreign Language High School, couldn’t wait to see her friends when South Korea reopened schools after a dozen weeks of distance learning.

The reunion lifted her spirits, but for the first few days, she refrained from hugs, just in case someone might be carrying the coronavirus.

School isn’t like she remembers, however, and Eun-jo’s routine, while still grueling by global standards, is very different.

After waking up at 6 a.m., she is required to fill out daily questionnaires on the country’s Education Ministry website, before going to school. Some questions: Do you have a fever of over 37.5 degrees Celsius? Do you have a headache?

Once the bus arrives, the driver checks the temperature of each student boarding. Students must sit apart for social distancing, something unimaginable in the pre-virus days, when sitting with friends was the norm. The government’s rotation system limits a third of the student body from going to school every day.

Arriving at school on her first day back, she was initially befuddled by the army of teachers greeting her and her friends.

Around 30 teachers stand daily in socially distanced lines along the street leading up to the school’s main entrance. They bark at students talking to each other and pick out students not keeping a one-meter distance from their classmates. School officials even marked yellow signs on the ground showing where seniors should walk, and where lower grades are to tread.

“I thought, wow, they’re really trying to make sure there’s no outbreak here,” Eun-jo said. She is one of more than two million South Korean students who returned to school last month. In Seoul, officials delayed reopening five times as new disease clusters emerged, though infections have slowed since peaking in February.

Being back in class is still a big relief, after months of studying alone, Eun-jo said. But gone are the team assignments that used to group five to six students for debates and projects.

“I kind of miss that,” she said. “Usually no one except the teacher talks in class now.”

Her school day ends at 4:55 p.m., instead of the usual 10 p.m. that she endured during the pre-coronavirus days. In South Korea, the late nights were due to a tradition of enforcing self-study sessions on high-schoolers once classes ended. A dinner break would provide the children with a much-needed breather in between the sessions.

“It feels like I was barely at school,” she said about heading home early each day, adding that she felt nostalgic for the longer days. “I miss being with my friends.”