This seems harder in our modern world where everything is contracted out to the lowest bidder. I've had great conversations with custodial staff at schools, parks, and other areas that actually hire the workers. At my day job, a giant corporation which hires its engineers but outsources its janitors, chefs, and so on, there's a totally different vibe.

Even the few janitors that speak English are both rushed to complete their tasks in the insufficient allotted time and almost terrified to talk to the normal employees, presumably due to the perceived power balance - were an employee to complain about them, the vendor would almost certainly fire them rather than risk offending the client. It's not fair, but it is reality, and it means that even when I do say hello or hold a door or whatever I don't get a response.