Also stop referring to a single individual as "they".
The singular "they" has been accepted in common usage for quite a while.
https://www.merriam-webster.com/words-at-play/singular-nonbinary-they
As a prescriptive grammarian, I consider it wrong since it violates pronoun-antecedent agreement. Despite predating Modern English, it is legitimately confusing in some instances. It's also not needed when referring to a hypothetical person who won't be offended (A person, the user, somebody). It also makes no sense when the speaker is certain of the antecedent's sex. It makes even less sense when a writer or speaker spontaneously switches between "they" and "he or she"; at least, pick one and stick with it.
This and not using the past participle in the present perfect and past perfect tenses are my two biggest peeves (e.g. "I should've went!", "I just got bit by a mosquito!"). EDIT: That last one is passive, not present or past perfect.