Miner snatched the police notice in his letterbox. "Fuck, not again." He quivered in rage. "The black people are at it again!" There had been a robbery in the area. Miner lived in that part of London derided as Poundland. Dirty parades of betting shops, twirling doner kebabs, payday lenders, unlicensed pawnbrokers and signs for "We Buy Gold". 

The cans were cracked open. Miner drank and grew flushed. There were six people living in two rooms. My friend, his girlfriend, and his father in one room. In the other Margarita the cleaner, her boyfriend (who had just lost his job at a recycling dump) and her tired mother. 

Polish builders are a little bit racist. London is probably home to more than 300,000 Polish migrants. But we can only roughly estimate that. So keen are they to save that little bit extra that many go under the radar to avoid tax. This is why every builder I spoke to on the site had been burgled. Their flats are always the cheapest, built with flimsy locks that can be undone in ten seconds. Sometimes landlords are in on the racket. 

Burglars love Poles because they are paid in cash and hide it in shoeboxes. When they see builders and cleaners moving in over the road, they are already laughing. They can sometimes make £5,000 from one bedsit. And they know the Poles will never call the police. 

Miner wanted to relax by showing me pictures of £5 million townhouses he had renovated. I was saved from this melancholy slide show by the return of Margarita the cleaner. She was too attractive to ignore. Like all cleaners, this girl from Bialystok likes to boast she knows everything about her homeowners. "I could hold them to ransom." She giggled. "I know the Clapham housewife who cheats because I clean the sheets. I know the Clerkenwell banker who loves cocaine because I find his powdered Oyster card." But cleaners never think of themselves as cleaners. They are always future professionals. They have big dreams about Britain, unlike their boyfriends, because they speak English. "Few of the houses are really dirty. Cleaners mostly are about polishing and keeping lonely housewives and old ladies company." 

These hours of unsolicited advice are the free English lessons and British crash-courses of Polish London. English unlocks London. Before long, many start flirting with the charming boys working at JD Sports. Those in love with Polish men start to tell them they want to have children here.