English has a fair few basic functional words that begin with a dental fricative, usually voiced: the, this, that, these, those, there; thou and thee are not commonly used, and when used at all are usually misused now; and, most controversial, they and them.
They is controversial? Sure – in fact, I’m tempted to suggest that it comes from +hey – it seems so likely to provoke an addition of “hey!” in some contexts. It doesn’t come from that, of course; in fact, it was originally spelled with a thorn (þ) where we now have th – fair enough for such a thorny word. But, beyond that, it’s not originally an English word.
Now, that little statement may surprise people who could hardly imagine importing a word so basic from another language. But have a look at the third-person plural pronouns from Old English (see http://faculty.virginia.edu/OldEnglish/courses/handouts/magic.pdf for as much information on Old English inflection as you could want):
nominative (subject): hie
accusative (direct object): hie
genitive (possessive): hira
dative (indirect object): him
Old English was, in its inflections, much more formally complex than modern English. The fact that the dative third person plural was the same as its masculine singular equivalent was not exceptionally problematic – German gets by with potential confusions between identical forms representing different persons and numbers, and we use you for singular and plural now in English. But during the Middle English period, all those inflections got simplified considerably, and so did some of the details of pronunciation. Meanwhile, in northern England, there was strong Old Norse influence (because of strong Scandinavian presence in the population!). The Old Norse third person plural pronoun þei, with its more distinctive sound, came into use, and by the end of the 1400s it had spread pretty much throughout England, displacing the older English form entirely – except for one survival: in unstressed, informal use, the him, reduced to ’em, is still often used in place of them, which requires more articulation. (Did you think this was just a simple deletion of the opening consonant? Ask yourself where else we drop that consonant at the beginning of a word. Answer: almost nowhere – it often gets lost in than after an /r/, as in “more’n” for more than, but that’s a specific conditioning environment.)
But that’s not the controversial part. The controversy actually comes from an issue with the singular pronouns. While in Old English all nouns had gender (masculine, feminine, or neuter), and so did the singular third person pronouns, by the end of the Middle English period only those pronouns retained gender, and gender had become linked directly to the physical human-male/human-female/non-human distinction (in German, which still has the genders, the linkage is not so absolute; for instance, a young unmarried woman is fräulein, which is neuter). But one runs into a problem when the sex of a person referred to is indeterminate. What does one do then? Well, you would think it wouldn’t be so difficult to swap in another related pronoun. And you’d be right: we do it readily enough with you in place of one, for instance, but also, for centuries, English speakers used they for gender-indeterminate third person singular, and no one complained.
For centuries? Oh yes – pretty much until about 1800, in fact. You can find it in the King James version of the Bible: “Let nothing be done through strife or vainglory; but in lowliness of mind let each esteem other better than themselves” (Philippians 2:3). You can find it in Shakespeare: “There’s not a man I meet but doth salute me, As if I were their well-acquainted friend” (Comedy of Errors IV:iii). It was common and unexceptional.
And then came the age of prescriptivism. Starting in the 1700s and gradually gathering steam and influence, there was a scholastic movement to impose rules and reason on English – of course those making this move failed to notice that English already had rules that worked just fine, and that the logic of languages is not inevitable mathematical. I won’t go into depth here on all the deleterious effects of their confected rules; you can read “When an ‘error’ isn’t,” “An appreciation of English: a language in motion,” and “What’s up with English spelling” for some more details on all this. But one thing their logical processes led them to was the idea that a plural pronoun couldn’t be used to signify a singular. (By this time you was accepted as a singular, so they evaded that issue.) And what singular pronoun could be used? Well, they thought he or she was inelegant, so of course, since – as people, particularly male ones, had been averring for some time – the male was the superior, the master of the female, etc. etc., it stood to reason the masculine pronoun should be the default.
And guess what. People bought it (along with a lot of other prescriptivist tut-tutting rubbish these cretins frankly invented). Oh, they didn’t swallow it hook, line, and sinker, not exactly. Fowler, referring to use of they and them and their for indeterminate distributive singulars (e.g., everyone took their book), noted “Archbishop Whately used to say that women were more liable than men to fall into this error, as they objected to identifying ‘everybody’ with ‘him’.” Gosh, those sensitive females! Tsk! But among their number we ought also to count such apparent males as Walt Whitman (“everyone shall delight us, and we them”), Lawrence Durrell (“You do not have to understand someone in order to love them”), C.S. Lewis (“She kept her head and kicked her shoes off, as everybody ought to do who falls into deep water in their clothes”), and Oscar Wilde (“Experience is the name everyone gives to their mistakes”).
And of course people still do it. People still do plenty of things that those benighted prescriptivists said are wrong. But many or even most of those same people who do them nonetheless believe them to be errors (everybody drives over the speed limit, even as they know it’s illegal, so why not use “wrong” language if it’s comfortable, eh?). And so we are faced with this battle. When, in the 1970s, women started getting people to listen to them (and by “people” I don’t just mean “men”; many or even most women before then didn’t listen to women on many important matters), they pointed out that use of man to mean human and he to mean a third person of possibly either sex embodied sexist assumptions.
And of course the response was that they were being oversensitive and making things up, and this was the way we had always done it and no had ever had a problem with it before. (When I was a youth, I certainly thought so; I couldn’t see why it was an issue that he was the neutral as well as the masculine, and at one point I may even have believed that it was a particular noble sacrifice on the part of males to forgo distinctiveness in lending their pronoun to generality. But I wasn’t female, so of course I didn’t see why it would be a problem – the have-mores very often think the have-lesses are whiners.) All of this was of course utterly false. But if a lie can be well enough established for long enough, people in general will assume it’s not just truth but time-honoured truth. So even today it remains a struggle to use they in many written contexts for gender-indeterminate third person singular. This in spite of the fact that few people admire the Victorians and their ideas of propriety generally.
Of course, the issue moves farther now, as in this egalitarian society we often question the need for gender distinction in third person singulars in any context. Many other languages do without such distinction, and we do without it everywhere but this one instance. When people wonder what pronoun we could use in place of he and she, various inventions are suggested, but the one already in use is they. Now, you may ask whether we could really manage with no singular/plural distinction. But you know, most of the time it works pretty well with you. I’m interested to see where this goes…
For much of the information above, I am indebted to two articles worth reading in entirety: Joan Taber’s 2006 “Singular They: The Pronoun That Came in from the Cold” and Ann Bodine’s 1975 “Androcentrism in prescriptive grammar: singular ‘they’, sex-indefinite ‘he’, and ‘he or she” (Language in Society 4: 129–146), and to Gael Spivak, who brought them to my attention.