‘They’ Has Been a Singular Pronoun Forever
Don't let anyone tell you it's incorrect
Anne Curzan is the Geneva Smitherman collegiate professor of English and linguistics at the University of Michigan, where she is also dean of the College of Literature, Science, and the Arts.
Some of the most open-minded, inclusive people I know struggle with the singular pronoun "they." And while it's hard to unlearn what we were taught was grammatically "wrong," it's worth doing. To start, let's clear away all the non-arguments that clutter the "they" debate to get to the heart of the matter.
Critics often start from the premise that "they" cannot be singular because a pronoun cannot be singular and plural at the same time. That argument is historically, socially and linguistically wrong. A pronoun most certainly can be singular and plural at the same time, as demonstrated by English's very own pronoun "you." And, when we look at the record, we discover the pronoun "they" has been used as a singular generic pronoun, alongside its plural uses, for hundreds of years. Shakespeare and Austen both used singular "they" this way, just as many English speakers do now. "But to expose the former faults of any person," noted Jane Bennet in Pride and Prejudice, "without knowing what their present feelings were, seemed unjustifiable."
In other words, the use of “they” as a singular pronoun, when the gender of the person is unknown or irrelevant, is nothing new. It’s considered wrong only because 200-plus years of grammarians have told us it is wrong, without solidly justifying that judgment. And whatever ambiguity the singular generic “they” may cause, it is clearly something speakers and writers can manage, as I will explain.
Please select this link to read the complete article from The Washington Post.