qbertThey/Them
I remember as a kid the teachers were desperately trying to make “he or she” a thing and told us the singular “they” would never be acceptable.
I’m personally glad that movement failed.
I learned English at school and the first time I encountered singular they was when my teacher explained it to us. Sometimes non native speakers are less prescriptive than native speakers
No, it’s just been a thing forever, and will always be thing. Those teachers, if they ever existed which I doubt, were just dumb fucks from Dumbfuckistan.