Never mind modern usage, OED traces it back to medieval English. https://public.oed.com/blog/a-brief-history-of-singular-they/ https://public.oed.com/blog/a-br

Never mind modern usage, OED traces it back to medieval English. https://public.oed.com/blog/a-brief-history-of-singular-they/ https://public.oed.com/blog/a-brief-history-of-singular-they...