I promised I would return to the vexed topic of using they or them or their with singular antecedents. Your holiday homework was to re-read the first act of The Importance of Being Earnest and comment. Richard Grayson (see the comments) saw the point immediately: Lady Bracknell remarks that at her last reception she wants music “that will encourage conversation, particularly at the end of the season when everyone has practically said whatever they had to say, which, in most cases, was probably not much” (underlining is mine). Everyone is the subject; the verb form has shows singular agreement; yet the pronoun she chooses is they.
The conclusion I draw is that singular they is fully grammatical, at least with quantifier-like antecedents such as everyone, nobody, etc. If Lady Bracknell is not the most intimidatingly formal speaker of Standard English in all of literature, I don’t know who is. We can’t dismiss her for lack of breeding. If Lady Bracknell uses a construction, I say it’s grammatical. (Or do you want to dismiss Oscar Wilde as unable to write grammatical lines for her to utter?)
One could say something similar about the real-life Lord Byron, who wrote contemptuously of Cambridge University: “Nobody here seems to look into an Author, ancient or modern, if they can avoid it.” The -s on seems shows singular agreement with nobody, which is the antecedent of they. Do the pedants really want to say that Lord Byron couldn’t make his pronouns agree?
One could go on. Shakespeare? Yes, he used singular they. Jane Austen? Large numbers of examples throughout her books. Who else? Perhaps the most telling example is that although Strunk and White’s The Elements of Style preaches against singular they, when E. B. White got back to his own excellent writing he wrote lines like “But somebody taught you, didn’t they?” (that’s from Charlotte’s Web).
What baffles me is how reluctant educated people are to take such facts as evidence. This is what I meant about Mary’s reaction to my usage. I’m not arrogantly assuming personal authority (though the commenter who uses the name “clarity_please” thinks I am, and others agree). Remember, I’m the one who pays attention to evidence from Oscar Wilde and Lord Byron and Jane Austen and E. B. White and huge numbers of other fine writers, not the one who pig-headedly insists on unquestioned dogma.
I’m not bossing Mary around concerning how to use her native language (that really would be arrogant); she doesn’t have to use they anywhere she doesn’t choose to. I’m just commenting on her amazing unwillingness to take anybody’s writing as evidence about what is grammatical, rather than as grounds for (however implausibly) calling the writer ignorant or careless. She clings to a sort of faith-based grammar: She thinks there are rules that we should follow even if native-speaking grammarians and fine playwrights and novelists disregard them—even if nobody in the world follows them (recall her remark: “No way shall I ever be convinced to change this in my writing or listening”). Why such a resolutely and hermetically theological view?
Some people clearly have an oversimplified misconception of the rule: “They must always refer to a group of entities” or something of the sort (“clarity_please” seems to have such a view). They write trying to explain to me, as if I were in elementary school, that “simple arithmetic” should tell me I am wrong. They seem not to realize that trying to suck grammatical truths out of naive conceptions of meaning is like trying to get blood out of a turnip. But they just stick with their misconceptions against all evidence, Wilde and Byron and Austen and White and Pullum be damned.
Some people may think I am pushing some kind of modern political correctness to avoid the apparent sexism of “Everyone should bring his own lunch,” but they are simply uninformed: singular they antedates modern feminism by hundreds of years. What I’m saying here has nothing to do with expungement of the apparent sexism of putatively sex-neutral he. It’s simply that I never cease to be amazed at such determined refusal to look at the evidence for English sentence structure the way we typically look at the evidence for, say, anatomical structure.
Normal people don’t say “No way will I ever accept the existence of a furry creature with a beak”: The discovery of the duck-billed platypus settles it against that opinion. When the topic is grammar, it seems that for some people nothing can ever settle anything.
[A brief update: For the people who have asked me why they takes plural agreement: "singular they" is an abbreviatory name, and it does not imply anything about agreement. They always takes the plural agreement form, regardless of its meaning; and everybody always takes the singular agreement form. That does not mean it's a contradiction for they to have everybody as its antecedent. Consider Everybody hopes that they are going to be the lucky one. The main clause subject everybody requires the singular form hopes; the subordinate clause subect they requires the plural form are; semantically, they expresses a bound variable; everything is as it should be. The sentence is fully grammatical.]