thee, thou, thy and thineAfter I'd studied "y'all" for a while I turned my attention to thee, thou, thy and thine. Most people have at least a basic background on them. They used to be informal ways of addressing people, used for friends and equals, similar to German "du" and Spanish "tu". Then Quakers mucked everything up by calling everyone by thee, thou, etc. and refusing to grant preferred status to the higher-ups, like tax collectors and royalty. THEN to avoid sounding like Quakers, English speaking society decided to just call everyone you etc., without regard to status. So what happened to thee, thou, thy and thine? Several things. First, they went out of common use; they were common in certain Quaker areas and Quaker communities for a while, and in some British dialects, such as Yorkshire and near Lancashire, but they have begun to fade, even there, recently.
Now this story gets interesting in several ways. First is, what little usage they have today, could basically be called "put-on religious" or "put-on Quaker." If you want to sound old, or hopelessly out of date, or rigid or moralistic in the sense that people see old Quakers, you might want to use them. People generally have lost track of the grammatical difference between "thee" and "thou" so they might use "thee" in subject position, or less frequently, "thou" in object position, incorrectly. They don't have a very clear sense of their grammatical sense, except possibly in the places where they were really used daily.
Then, I asked the Quakers what they thought of so-called "plain speaking"...how could it be that, if it's called plain speaking, it's really only used in a "put on" way? Quakers are by nature opposed to pretentiousness, thus they shun such things as creating an in-group, putting on airs of any kind, or trying to "sound" as if they were something they're not. So, are these words doomed? Yes, in the Quaker community anyway. If they sound put-on, Quakers aren't going to use them. Period.
Such it is that the opposite has evolved from what was, at one time, "plain speaking." If it is no longer plain, it is on its way out, and if any group chooses to start using it on a day-to-day basis, to create an ingroup, religious or not, or for any other reason, I'd like to know. It's a system, and, without wanting exactly to go back to the days of King James, I really would like to know how it sounds in an everyday kind of way.