Recently, I have had occasion to revisit an issue of grammar. It was not an issue in my mind but it arose in a discussion. I am going to try, mightily, to remain brief, but unequivocal. In short, the use of the word, "they" in sentences that have singular subjects is, sometimes being defended as a legitimate mutation of "they" into a singular word. Here is most of the argument for this position. It begins with the old grammatical supposition that "they" is actually a plural pronoun. Here is Michael Quinion's answer to that reasonably settled use:
"Unfortunately, it's not the way that reputable writers have used they, their and them down the centuries. It is possible to find examples of such pronouns used with singular nouns at least as far back as Chaucer. The problem is that English doesn't have a gender-neutral pronoun to cope with those cases in which we know little about the person being referred to. Many writers have happily got around this by using they and its relatives as indefinite pronouns, especially after words such as anyone, everyone, someone and no one." (M. Quinion, 2006, World Wide Words, Comments and feedback.)
In addition, the old use of the word "him," which was the original recommendation of the 18th through early 20th century grammarians, is dismissed as "sexist." Strangely, "him or her" or "her or him," are not mentioned, although this was the recommendation for a large part of the last century.
I wish to start to answer this in so many places that I am virtually paralyzed by choice. I shall, therefore, simply characterize my response to it in general. It is unmitigated, utter, unimaginative, absurd nonsense. And, I don't agree, in case that was unclear. Where to start? First of all, in the works referred to, it was generally not, "they" that was being used as singular; it was. "everyone, everybody, anyone, and anybody" that were being used as plural (to which, incidentally, I have slightly less objection). Often, however, in the sentence containing the conflict a singular verb will be used, which might have given rise to the strange statement about the singular, "they." Secondly, what is the matter with gender neutral subjects such as, "all, people, all people, those, and several other words that can be used in the subject of all of the sentences that are in question? The entire sentence can, always be converted to plural, if plural is what is meant, as it usually is, in these constructions. I will concede that "his or hers," or its reverse and similar constructions are a little awkward in the flow of some writing. So what? It's better than changing the meanings of words or committing frank errors.
If there is an issue in which there is a gap that a "singular they" would bridge, it comes in a somewhat more complicated sequence than is usually given to illustrate the problem. It arises in a situation in which the speaker is unaware of the gender of one individual and refers to that person in a second clause or a second sentence. "Someone stole my wallet. If they return it, I will not prosecute." Or, in a common construction such as, "Would you say that anyone who wants to adopt a child, if they could do it faster, wouldnt they?" (I couldn't resist. As I was typing, Larry King just uttered that beautiful example. Oct. 18, 2006.) In the first instance, the solution in the previous sentence can be used, in which, "that person" was the chosen singular referant. In the second sentence, both a plural construction or the substitute of one of the singular phrases for the word, "they," would solve the problem. Awkward? Yes, a little but both constructions can be rewritten to avoid the problem and the awkwardness. Any solution is better than declaring "they" to be an (optionally) singular word.
However, my base objection to this type of acceptance is much broader than this issue. Even if all of the arguments tendered were true, and they are not; even if there were no simple exits from this (non-existent) problem; even if it were not a misconstruction of how the words were used, it remains an instance of the rules of grammar, syntax, and the very root meanings of words,' being driven by common error. Elsewhere, I have hinted about my feelings regarding that.
You know what, people (all, readers, etc.)? "They" is a useful word in the English language, just as it is. When it is used, in any context, it tells the recipient that those being described, number more than one. We do not need it to be ambiguous. We do not need to change the meaning of established words in order to accommodate people who cannot or will not conform their sentences to perfectly good and appropriate grammar. If most people thought that a trillion meant, "lots," and we accepted that, we would have some gaps in math, as does the federal government now, who uses it to mean, "a little." Just because English is not as precise as math and because it does evolve, we do not need to decrease the precision even further for no reason apart from the error of writers too lazy or ignorant to rewrite their sentences, and that includes Chaucer.
All I can say about those people (gender neutral, plural) is," They is wrong."