About 5 years ago, some fellow grad students and I had a fairly recent Guatemalan immigrant serving as the janitor in our part of the building. It was basically awkward all around: the janitors normally came in late-ish to vacuum and empty trash cans and such, to avoid being there when most of the employees were, but grad students, especially in CS, work pretty random hours, so we were often there at 11pm or whatever. The guy spoke no English, and none of us spoke more than about 30 words of Spanish, but somehow given our life positions, none of us were comfortable totally ignoring another human who came into our area (I imagine some people are more used to doing so). So there was always this awkward attempt to say hello and make smalltalk, which mostly ended up in Spanish because the grad students knew a tiny bit more Spanish than the guy knew English.
He actually seemed pretty happy about that interaction happening at all. At some point, though, we ended up collecting like $200 and a card for Christmas (perhaps we felt a bit guilty that he came around emptying trash and vacuuming while we were doing a mixture of procrastinating on Bejeweled Blitz and maybe sometimes writing papers), which he found amazingly surprising. From our perspective it was quite strange that we were capable of making a gesture that made someone surprised/grateful, because I mean we were poor grad students, which in our context was a low-money/low-status occupation.