A small group of boys play football, dodging tangled metal in the ruined Umayyad mosque of Aleppo’s old city. When they were last able to come here, before the war, the vast courtyard’s patterned floor was beautifully polished, and the pile of bricks in a corner was a millennium-old minaret.

Now, the boys pick at the sandbags piled in its huge, fire-blackened arches. For them, this ancient place-of-worship-turned-fortress is a playground in a hellscape.

“It seems bigger now, maybe because I didn’t see it for such a long time,” says Yamin Saeed, a sweet-faced 14-year-old in a fake Armani jumper. Before the war, he and his friends were like children anywhere – they went to school, they loved Tom and Jerry – but the battle for Aleppo aged them overnight.

“I saw a human head once,” says Mohammed Sheni, who is also 14. “We were walking and then there was a rocket and people died. I’m trying to forget it, but you can’t forget something like that.”

Fourteen-year-old Yamin Saeed hangs out with his friends in the ruins. Photograph: Ruth Maclean/The Guardian

It is a windy day. The boys walk home, steering clear of the narrow back streets to avoid dangling steel and falling concrete.

Amid a countrywide uprising against Bashar al-Assad’s government, rebels took control of Aleppo’s eastern half in 2012. In the following years, it was held by a mishmash of different groups, often at war with each other as well as with forces loyal to Assad.

In September 2015, pro-Assad Moscow launched airstrikes in Syria, starting in Homs and Hama, two cities north of Damascus. After that, Russian air power helped turn the tide against the various anti-government groups with a sustained bombing campaign on east Aleppo.

Walking in the city now, the toll exacted on its ancient streets by the war between pro-government forces, rebels and jihadis is evident, as is the human toll signified by the silence. Residents say they know the remains of their neighbours are still trapped under layers of rubble.

In December 2015, a truce allowed the evacuation of besieged citizens and, for a few days, the east was completely empty. But then people began to trickle back. Those remaining – who have nowhere else to go or feel pulled to their homes – go about their lives amid the profound destruction.

At the moment, that means just trying to survive. Everybody gets up and goes to bed with the sun because there is no electricity, and wears all their clothes at once to keep warm.

In the men’s queue for hot food handed out by a charity, all the young men are gone. Photograph: Ruth Maclean for the Guardian

At 10am in al-Shaar, a neighbourhood ruined by years of bombing, men and women queue separately in the street by pots of steaming rice and chickpeas, clutching small plastic tubs, waiting for the representative of the charity handing food out to give them a few ladlefuls to feed their families for the day. When there was just one queue, explains the man doling it out, there was too much shoving. The women’s queue is four times as long as the men’s, which is really an old men’s queue – wrinkled faces under red and white keffiyehs. There are few young men left here.

By the end of the siege, only about 40,000 east Aleppians were still living there, of a pre-war population of about 1 million. Some moved to the west early on, or elsewhere in Syria, or left the country. Nobody knows how many were killed.

Turn down any street and one house might be a mess of metal rods and stone; the next still standing but inaccessible because the stairwell has been bombed; the next burned out and missing all its windows and doors.

The al-Bayan hospital has lost almost its entire facade: it looks like an open doll’s house. Brown armchairs sit in a waiting room, shelves are full of files.

A doll’s house ... the al-Bayan hospital in east Aleppo. Photograph: Ruth Maclean for the Guardian

The core of another building is still standing, but with no outer walls to support them, the floors flap down, trapping sofas and mattresses at odd angles. A dusty television stands on a sideboard on the third floor. A pink toilet with an apocalyptic view is visible on the fifth. People’s disfigured lives are on display.

But those people are almost all gone.

“This street used to be full. Now there’s only us and a couple of other families,” says Umm Ahmad. When I introduce myself to her in the deserted street, the first thing she says is: “My husband was killed over there.” Four years ago, he was hit leaving their mosque, which has a great hole in its dome. Ahmad lives with her father-in-law and her five children in a tiny flat that is more intact than most, but is missing windows and great chunks of the balcony.

We step over the pulverised remains of her neighbours’ flats and their contents, through her decorated, dented front door. She shows me into her lounge, UN tarpaulins pinned up to keep the weather out.

Umm Fardel, one her last friends in the neighbourhood, lost her house and everything she owned and laughs about her misfortune.

“Everything my husband and I built for 20 years, just gone in the blink of an eye,” she says, shaking with giggles on Umm Ahmad’s armchair. “Why should I be sad? I’m not the only one.”

“Someone stole my husband’s taxi, so now he’s always at home looking after me. I’m getting fatter and fatter,” she continues.

Umm Ahmad says: “We are laughing and crying at the same time.”

Her 20-year-old daughter, who is about to get married to a soldier in the Syrian army, hands round hot, spiced coffee in tiny ornamental cups. She does not mention it, of course, but this generosity comes at a cost: the water has to be fetched from tanks at the end of the street, and the fuel to boil it bought.

“Before, we pressed a button and we had hot water. I could wash my hair, just like that,” Fardel says.

As you drive from the east to the west side of Aleppo, past billboards of Assad and Putin wearing hard expressions, the universal destruction turns into a bustling, intact city. “Night and day” is how many describe the difference between the two sides.

In the west of what used to be Syria’s economic capital, hundreds of shoppers browse market stalls selling everything from marzipan fruits to towering glitter heels. Fairy lights adorn the trees outside bars and restaurants, where clients flirt, smoke their water pipes and order bottles of Jack Daniel’s. An orange tree stands, leaves glistening and branches full of fruit. In the war, most of the east’s trees were chopped down for firewood.

Assad and Putin watch over from billboards between the east and west of the city. Photograph: Ruth Maclean for the Guardian

After the siege ended, the boys hanging around the Umayyad mosque went to look at the west. They found a city that had carried on without them.

“In east Aleppo, there was no meaning to life. In the west, they were alive. But now we’re trying to get our lives back,” Yamin says.

People living in the west are not without their problems, of course – water and electricity have to be purchased, and as the Syrian pound is at a fraction of its pre-war value, they can easily eat up a third of a salary.

At a packed bazaar in a once-plush, now tired hotel in west Aleppo, art teacher Obaida Qudsi gives visitors to his exhibition glow-in-the-dark stickers, so they can find their mobile phones in the middle of the night, when generators are off.

Qudsi proudly tells passersby that he is the maker of the world’s largest paperclip, unveiled at a Dubai shopping centre in 2004. In fact, his 3m paperclip was overtaken by a 9m Russian one in 2010. It is hard to imagine this kind of talk in the east, although it is less than two miles away.

Qudsi does not have to endure life in Aleppo: he has papers that mean he could go and live in the UAE. However, he says: “It’s my home, and if everyone goes, who will stay?”

Perhaps he would make a different choice if he lived in the east of the city.

Whether people say what they think or parrot government lines can be hard to judge. Journalists going into Assad’s Syria are assigned a government minder, who follows them around, listens to interviews and reports back to the ministry of information. Hearing what happened to others who opposed the government, it is hard to know how honest east Aleppians who live surrounded by army checkpoints and Assad’s face gazing down from posters can be about, say, whether they sympathised with the rebels, or what they think of the president.

A school has just reopened to educate children who have been hiding at home for years. Photograph: Ruth Maclean for the Guardian

Sometimes the propaganda is subtler.

A school has just opened amid the destruction. Children who have been hiding at home for years hare around its courtyard at break time. There is no water, so those who need the toilet leave the building, go down the street and disappear behind chunks of jagged concrete.

One teacher, Riham al-Hamoud, complains that there is too much variation in ability in her class of eight-year-olds. Many of the children in east Aleppo during the siege went to religious school or not at all, she says.

“The aggressive ones, and the ones that don’t want to learn, are those who were out of school for a long time,” she says, looking at the government minder behind me as she speaks. “They lived in war, they spent their lives watching clashes and seeing planes bombing. They didn’t have the chance to play.”

Teacher Riham al-Hamoud: ‘The children say: “Should I tell you what happened in the siege?” And I say: “No. Let’s talk about nice things.”’ Photograph: Ruth Maclean for the Guardian

Hamoud’s first priority was to teach them the true colours of the Syrian flag. Then she tackled behaviour.

“They were very dirty in every way. They were throwing rubbish in the garden. I taught them not to,” she says. She puts this down to their parents, who she says were “affected by black-minded people”. This, “weapons carriers”, “the armed opposition” and simply “those people” are all phrases people use to refer to the rebel groups.

If anybody tries to talk about the horrors they experienced during the war, she says, she stops them.

“The children say: ‘Should I tell you what happened in the siege?’ And I say: ‘No, I’m not interested. Let’s talk about nice things.’”

Juman Makkie, head of the Orphaned Girl institution in west Aleppo, uses the same approach with her war-scarred wards: “We don’t open old stories with them. We have to close the curtain and not look back. It works 90% of the time. With the other 10%, we persevere so that they forget – or at least that they don’t mention it.”

Out loud, at least, a generation of Syrian children is learning to look forward, and not dwell on the past – even the past of only a few months ago. For most Syrians, the way you talk about the past could get you in trouble.

Most Aleppians have no idea what the future holds for them.

Umm Mohammed is relieved that her family managed to secure two rooms in the overflowing Jibrin refugee camp, where they plan to stay until they can work out what to do next.

Not everything in their future is on hold. The family’s 18-year-old second son got married two days earlier – to a 13-year-old girl, who stands awkwardly by her marital bed, a pile of shiny cream cushions and duvet on a mattress on the floor, looking fixedly at the mat.

Umm Mohammed and her 13-year-old daughter-in-law, on the marital bed she put together for the couple. Photograph: Ruth Maclean for the Guardian

“I cleared everyone out of this room for their wedding night,” Umm Mohammed says, taking her phone out and flipping through photos of the ceremony, which took place in the same room. In them, her child of a daughter-in-law poses in her bridal gown, her face white with makeup, pouting, her forearms resting on the wall of what used to be a workshop.

Asked why the couple married so young, Umm Mohammed says her firstborn son was murdered for being a government spy, and she is hoping there will soon be a new boy in the family.

As dusk approaches, Aleppo’s once-clear air is tinged yellow with the dust from fallen buildings.

In the east, it casts a haze over the Umayyad mosque. Even after Yamin and his friends have tramped home, Aleppians of all ages keep arriving. They have not come to pray: they are curious. They peer at the ornate tiles of a shrine, at the broken taps where worshippers would wash, at the polite pre-2011 notice to remove shoes, which is half shot off the wall.

In the west, drivers on their way home from work brush it from their windscreens rather than washing it off, to save water. The dust coats everything, east and west, uniting the two halves of the city.