"It's okay" isn't what I mean by a "rule": I'm talking about the kind of "rule" that tells me (or any other speaker) when to use "they". There certainly are pe

"It's okay" isn't what I mean by a "rule": I'm talking about the kind of "rule" that tells me (or any other speaker) when to use "they". There certainly are people using "they" when they know the gender, but they don't use "they" in every case, as far as I can tell, so presumably they are following some kind of rule with conditions in it (because people don't, in practice, choose pronouns at random).