English has always used they, their and them in the aforementioned cases. While I can't give citations off the top of my head, I suspect the proscribed usage goes back to the prescriptivists of the 18th century, possibly earlier, (Although I don't want to blame Dryden any more than he has been).

Maybe, but I can still do without such usages as "every man should find out for theirself" or even "...theirselves." Or "the woman said their purse was stolen."

Well, theirself is still considered nonstandard/ungrammatical, and the second example is merely maladroit. You can also find perfectly grammatical sentences in standard English that are ungainly and painful to look at.

I usually choose the gender-neutral they/their unless I have some dislike for the individual in question. In those cases, I tend to use the construction "s/he/it".

It's pronounced exactly the way it's spelled...

Zwicky had an interesting series on the Language Log in which he, in essence, called editors' bluff on the issue of ambiguity:

http://languagelog.ldc.upenn.edu/nll/?p=205

"The usage manuals are full of condemnations of forms and constructions on the grounds that they could lead to ambiguity [...] almost without exception, these protestations are without merit; the usages in question are innocuous, and the awful examples are deeply decontextualized — with no linguistic context, and usually with cues to the social and cultural context removed. [...]"

I am a purist who has been dragged over the finish line wrt the singular "they". No it isn't vague. At the same time, it is and always will be an agreement violation. Death will cure my discomfort with the notion of trumping grammar rules. (If we snapped a twitpic today of the invasion of grammarlessness, how much of the camel is in the proper usage tent, oh you defenders?) My deep reverence for grammar is based on the conceit that internally there is a thorough logic to it. Is English grammar a glorious organic system, or is it a contrived artifice that appears integral only to one reared inside it? Although I would propose that the former is the case, I don't have the formal training to defend one position or the other. My sons could give a rat's ass. Maybe "they" and "their" are merely a crack in the liberty bell, which remains perfect anyway.

One use that I will fight to my dying breath is the nearly fully accomplished substitution of "that" for "who". a) there's no good reason for it, and b) "that" as a demonstrative for a person is symptomatic of the ascendant presumption that all is material, period. Symptomatic, in my view, of the fossilization of humanity that we are inadvertently courting today! So come on people: fight for "who" and "whom".

Yes!

Drives me batty every time I feel I have to change "their" to something else because it's Copy Editor Canon Law

With respect, Mr. Sanger, I believe you have it backwards. English does have a grammar and set of rules, a deeply organic system. But some of the things that people understand to be rules are inventions, like Dryden's prohibition of prepositions at the end of sentences, intended to make the language more "correct."

As for your distaste for that for who, let me trot out yet again my suggestion that Bishop Lancelot Andrewes and the other translators of the Authorized Version were not contributing to the "fossilization of humanity" when they translated Isaiah as saying, "The people that walked in darkness have seen a great light."

If I agreed with Mr Sanger about the logic of English (and, believe me, I'm tempted) I'd think that a rat's arse is what his sons in fact couldn't give.

You've summed it up nicely in your closing lines: "We already have a gender-neutral pronoun that has fulfilled this function since the time of Caxton and Chaucer: they/their. So the sensible thing to do is to abandon the stricture against it from your fifth-grade English class."

I think Lewis Carroll had it right. Doesn't it all come down to words meaning what we say they mean? If enough people agree on the meaning, then that's about it for establishing how a word can be used to convey that meaning effectively. I figure if enough of us agree that "their" is both singular and plural, then it is. To the hidebound who say "But I don't want it to mean both things," I respond, "Tough beans, baby."

Tim

P.S. It's also tough beans when one of your friends and supporters, Mr. McIntyre, is among the hidebound. Martha Brockenbrough, in "Things That Make Us [Sic]," criticizes Jane Austen's use of the singular "their" as bad grammar, suggesting that even the greats get it wrong sometimes. I don't doubt that they do, but (as you note) this is not an example of it.

My favorite singular/plural error, made by Ann Romney (just before the January 2008 Iowa Republican caucuses; heard on C-SPAN radio) who started a sentence she just couldn't finish without getting into trouble:

"The heart of the people of Iowa ... are good."

As it's been used forever as a singular in this way, I don't regard it as a plural for which an exception is made; rather simply a singular form that happens in this instance to be exactly similar to a plural. Since English is so short of inflections there are many that do multiple duty -- this happens sometimes even in languages that are richly inflected. A little re-think and the peeve vanishes in a puff of absurdity.