Evolution of Third-Person Singular Pronouns in English
Language is constantly evolving. We add new words, and we adjust the ways we use old words. This happens a lot with nouns, verbs, adjectives, and adverbs, but we don't see it happen as frequently with some other categories like pronouns (me, your, etc.) or conjunctions (and, but, etc.). There have been some notable changes to the use of pronouns, though, and those changes are related to gender.
A few decades ago, it would be pretty common to see a sentence like this: