Mark, in the comments to an earlier entry, brought up an interesting point: why did the “thou/thee” form disappear from English (except for a few dialects)? There is a fascinating discussion of this on LINGUIST List, from which I quote the following, by Larry Trask:
English-speakers began to use ‘you’ as a respectful singular in the 13th century, probably under French influence. Except in conditions of intimacy, ‘you’ quickly became established as the ordinary way for an upper-class speaker to address an equal, as well as a superior, and by the 16th century ‘thou’ was all but non-existent in upper-class speech, except in addressing obvious inferiors. Naturally, this usage began to be copied by the middle class, and by the 16th century ‘thou’ was likewise rare in middle-class speech, except in addressing obvious inferiors. But ‘thou’ lingered long among working-class people, especially in rural areas, and it still survives today in parts of the north of England, where it has reportedly become something of a badge of solidarity.
None of this requires any particular explanation, but one point does: why did the non-reciprocal use of ‘you’ and ‘thou’ in power-based relationships disappear? Now, as Brown and Gilman argue in their famous paper ["The Pronouns of Power and Solidarity." In Ed. T. A. Sebeok. Style in Language. Cambridge, MA: MIT Press, 1960. 253-277], there has been a steady trend (now mostly gone to completion) in European languages to replace the older non-reciprocal power-based use of T and V pronouns with a newer reciprocal solidarity-based use. Something similar appears to have happened much earlier in English, with the added twist that `thou’ was driven out of the standard language altogether. Nobody knows why, but Leith has an interesting suggestion. He proposes that 16th-century England, in comparison with most other European countries, was characterized by a fluid and prosperous middle class, in which rapid rise was possible by entrepreneurial success. England, he argues, therefore lacked the comparatively rigid social structures typical ofother countries, at least as far as the middle class was concerned. Whereas every speaker of French or Spanish knew his own station and knew that of everyone else, so that power-based non-reciprocal usage could be readily maintained, a middle-class English person was by comparison insecure: he could never quite be sure whether a stranger was an inferior, an equal, or a superior. Therefore, Leith concludes, the reciprocal use of ‘you’ rapidly took hold among the middle class as the safest option, as a safe way of avoiding giving offense to a person one might need to do business with or ask favors of.
Another discussion includes pronoun distinctions in Italy, Belgium, Australia, and Providence (Rhode Island), and an article on the subject by Sara Malton includes a bibliography for those who wish to pursue this intriguing issue further.
Addendum. There is a discussion of this going on at Page of Moss; no Korean yet, but lots of Mongolian and Buryat, as well as a reference to the prerevolutionary honorific use in Russia of the third person plural for a single individual: a housemaid, asked if her master were in, would reply “Yes, sir, they are.” Also, Karin has this to say:
In Norwegian it is du – informal and de – formal. I always found it a pain in the neck. De always felt awkward to me, but as a child I was supposed to use it when talking to grownups: teachers, my sister’s in-laws, the tramcar conductor, neighbors—you name it. It was such a relief coming to the US and just say you. Easy, comfortable, no (class distinction). Thank you English!
I have also found a discussion of the polite-pronoun issue here; Mark J. Reed is investigating the matter and presumably will put a summary of what he learns online when he learns it; the phenomenon of voseo (use of the singular pronoun vos as a neutral form of address, avoiding the choice between tú and usted, used in Argentina and Uruguay and less widely elsewhere) is described here (some illustrations here); and Mikhail Epstein discusses the ideology of Soviet forms of address, including Vy/ty, here (scroll down to CHAPTER 9. IDEOLOGICAL SYNTAX: FORMS OF ADDRESS). A sample:
Ideological language, however, most often combines the familiar pronoun with the formal name and patronymic: “ty, Aleksei Nikolaevich.” This form of address is the norm between members of the Communist Party, even in the Politburo. Such a combination reflects the two-fold nature of ideological language: in addressing an ideological brother it is impossible to use the vy form, but since this “brother” is not a blood-relation, it is necessary to retain some element of formality when addressing him. The element of formality was strengthened when ideological language became the official language of Soviet society. Ideological language is thus simultaneously brotherly and official, a combination of familiarity and formality.