English has two main words for people one knows — acquaintance and friend. Russian has three: znakomyy, which has the same root as acquaintance, droog, which is generally translated as friend, and priyatel’, the root of which is the same as the root of the Russian word for “pleasant”; priyatel’ thus means something like “someone with whom it’s pleasant to be,” and means something between znakomyy and droog. People one knows are thus conveniently sortable into three categories, rather than just two. (You can also say “close friend” — “blizkiy droog” — just as you can in English.)
I have no reason to think that this extra distinction either makes or reflects a real difference between the Russian culture and the Anglophone cultures. But I have always quite liked it.
Of course, in Russian (like in other languages) there are also two singular “you”‘s — the informal “ty” and the formal “vy.” In English, the distinction once existed (“thou” was the informal, “you” the formal) but is now largely dead. In some other languages, as I understand it, it’s also vanishing, with “you” being used even for close friends. But in Russian, it’s alive and well.
Because of it, you have to know for each of your acquaintances whether you’re on “ty” terms or “vy” terms with them, just as you have to know in English whether you’re on a first-name basis. And it’s not safe just to assume one or the other when in doubt: If someone has offered to be on informal terms with you (“switched to ty”), then it’s considered something of a slight to use vy with them, just as it’s considered a slight to use ty with someone to whom you should use vy.
Worse still, because there are different verb endings for each pronoun, you can’t fudge it just by omitting the pronoun — as you can fudge things in America by just not using a person’s name when speaking to them, if you’re not sure whether to use the first name or Mr./Ms. last-name. Rather annoying, I’ve found (though maybe that’s because I’m unusually forgetful.)
UPDATE: A reader asks “So what’s tovarishch”? Tovarishch literally means comrade, though it sometimes has the connotation of buddy. (I’m not quite sure what the most common connotation is in today’s Russia, but I’ve heard it both in a Communist or mock-Communist context, and apolitically as buddy, especially when used in the third person.)