I found this very beautiful and subtle example illustrating the use of singular-antecedent they in a passage (here) written (or more likely dictated — this sounds like speech) by the distinguished BBC Africa correspondent Ofeibea Quist-Arcton (photograph here) for the BBC, which asked a number of foreign correspondents to write something about awful travel experiences in Africa (I take the liberty of adding underlining on the anaphoric pronouns I want to talk about):
One of my favourites is when you are sitting on the aircraft and you just happen to have a free seat next to you - and you think, "my goodness, I can lie down and sleep after one of those heavy assignments".
And then as you begin to relax, you see one of those huge West African traders, she could be from Ghana, Nigeria or Senegal or Togo, you name it.
Then you hear the footsteps coming down the plane boom, boom, boom and then you hear move over! Their 25 kg luggage is hurled onto your lap, their boom box is pressed against your shoulder.
You all but carry their clothes on your head, whilst of course this very, very determined woman, who is going to sit right there, tries to shove her stuff into the overhead compartment - but there is no room left.
So you end up carrying her stuff on your lap - and that's how your two-hour trip is going to end.
The first she has the antecedent one of those huge West African traders. At that point the trader in the remembered anecdote is a woman visible down at the front of the plane, waiting to get down the aisle to find her seat. The appropriate pronoun for a woman you can see is she. But our narrator still thinks she will be lucky and spend the flight beside an empty seat. Perhaps she closes her eyes to rest as the rest of the passengers board.
Then footsteps are heard ("boom, boom, boom"), and a voice ("move over!") is heard, and at this point (imagine you still have your eyes closed) the producer of the pounding footsteps and stentorian voice is an indefinite individual suitable to be referred to with singular they. The genitive form of this pronoun (their) is used three times (you can almost see Ms Quist-Arcton struggling to keep her eyes closed, to pretend that she's asleep and this isn't happening).
But the moment the phrase this very, very determined woman has been used, we are back in a situation where the grammatical demands of English call for the feminine pronoun: although I am always prepared to be surprised, my assumption is that you simply cannot say anything like *The woman said they were unhappy with they referring to the woman. (Compare if your partner says they are unhappy, which plenty of people would use to allow for partners of either sex.) So the final two pronoun references to the monstrous trader woman are forms of the feminine singular she (the genitive form, her).
This back-and-forth alternation between forms of she and forms of they and back again is unusual, and I'm not recommending it as the perfect style for carefully prepared serious prose. But it offers a beautiful glimpse the dynamics of pronoun choice. The use of singular-antecedent they is extremely subtle, and I'm not going to offer a hard generalization. But we see here that it is used when it is possible to imagine being mistaken about the sex of the referent or when the sex of the referent is indeterminate, for example, when neither details of the actual referent nor details of the noun that occurs as the linguistic antecedent make feminine or masculine pronoun gender a necessity.
So when a woman appears at the front of the plane and you can see she is a woman, you have to refer to her with she for pragmatic reasons. When you hear an unknown person approaching, they can be referred to using they, even if they get close enough to press their boom box against your shoulder. But the moment you acknowledge that you are going to be seated next to this person, and she is a woman, and you're going to help her by carrying fifty pounds of her cabin baggage on your lap, and you acknowledge the situation linguistically by referring to her with the word woman, the pronoun she has to be used from then on for grammatical reasons.
There is a subtle and beautiful system here. It is not to be dismissed with the idiotic sexist authoritarianism of Strunk and White's The Elements of Style (p. 60: "Do not use they... Use the singular pronoun... he), which so many Americans believe is gospel.
Quist-Arcton, by the way, has an extraordinarily clear, refined, impeccable, BBC British accent. As Mary Macfarlane of the University of York reminds me, it is often the case that British speakers are more comfortable with the English language as it is, and hence less prone to believe ill-informed prescriptive nonsense about what's "bad" or "wrong" in usage. Scores of literary citations can be given to show that singular-antecedent they is common in good writing as well as speech; but most of the literary sources are British; it is American writers who are more inclined to live in terror of the usage fascists.
Posted by Geoffrey K. Pullum at December 14, 2004 12:54 PM