I have a goodly number of pet peeves, as anyone of my disposition would have. But I just read something where a young woman was discussing how “you” can be singular or plural, and therefore “they” should also be accepted as referring to both singular and plural.
It reminded me of a Latin pet peeve of mine, specifically having to do with Latin to English translation.
When I see verbs with specific “you” singular or plural (for example -t/-tis, -it/-itis, istī/-istis, etc), I absolutely demand that this difference in included in the English translation. If it is a plural “you,” it must be translated into “all of you” or “you all” because simply putting “you” to indicate both singular and plural is misleading and could confuse translation and meaning. And if the translator fails to translate it just so, I will write it in for them.