Languages evolve and transform. If that weren’t the case, the only word in the previous sentence that would be considered English is and (which in any case used to mean if). The English we speak would not be remotely comprehensible to Geoffrey Chaucer, who wrote The Canterbury Tales some 600 years ago.
Contemporary accents in particular would sound very foreign to Shakespeare’s ears, and the grammatical structure of the language has changed in subtle ways in the 400 years since he died.
For the most part, those changes don’t affect the expressiveness of the language or the ease of making certain important distinctions in speech and writing. Yet language-change is not consciously guided: it’s unpredictable and sometimes chaotic. So what if language change gets it “wrong”?
Contemporary Standard Englishes (UK, USA, Australian, NZ, SA etc) distinguish singular from plural for all nouns and pronouns, with a few exceptions:
The few exceptions among nouns – such as “sheep” – rarely, if ever, cause confusion or lack of clarity. The problematic case is the second person pronoun “you”. All the other pronouns not only vary from singular to plural, but also generally have distinct forms that vary for “case” or – put simplistically – whether the word is the subject or object of the sentence:
“I love language” versus “language fascinates me”.
The second person is simply you, whether singular or plural, subject or object. But that wasn’t always the situation. As recently as 400 ago, second person pronouns were as follows:
You took over as the plural form for both subject and object, but then eventually also supplanted the singular forms, so that we now no longer can be certain whether sentences such as “I need you to help me” is directed to one person in a group or the whole group.
We can of course get round it by adding phrases such as “You, with the blue shirt” or “you boys,” but compared to the elegant thou versus you this is clunky, and the verbiage almost defeats the advantage of having a pronoun, a shortcut to reference, in the first place. It’s a very useful distinction.
How on earth did we lose it?
My favourite hypothesis is that it fell victim to the increasing taste for formality in English-speaking society in the 17th through 19th centuries. You in Shakespeare’s day was not only used for the plural, but could be used to address a single person in a formal context – usually if the person was of a higher social status or rank than the speaker, or if they were a stranger of presumably equal rank.
The use of you to a singular person indicated a kind of deference and social distance, and was formal in tone. One might say “I have brought thee a cabbage” to one’s brother or friend, but “I have brought you a cabbage” to a king, bishop, or employer (unless on intimate terms).
Many languages, such as French, still do this – they maintain a distinction between singular and plural second person, but use the plural form (vous) to a single person to indicate politeness or formality.
When I first read Pride and Prejudice, I was astonished by Mr and Mrs Bennett, married for decades, alone at a breakfast table, addressing one another as Mr Bennett and Mrs Bennett. It’s not outlandish as an expression of endearment (as some couples use Mum and Dad to one another), but we can presume that a writer as astute as Jane Austen would have been reflecting social concerns and trends.
From my non-expert reading of the history of these times, it seems the level of formality increased in all interactions, even the most intimate, after the Renaissance, reaching a zenith in the Regency and Victorian eras.
People would have used the formal second person you in more and more contexts, and the familiar/intimate thou less, until a tipping point was reached and the singular forms disappeared entirely.
Contemporary English-speaking societies have retreated from that level of formality. Even the most formal interactions, such as job interviews and audiences with dignitaries, are far more casual than they were 200 years ago. Plus, we lost our means of distinguishing with a mere word whom exactly we were addressing.
That’s why, independently in many varieties of English around the world, the distinction has been re-introduced. Not by the resurrection of thou, but by keeping you as the singular, and introducing a new plural such as youse (Australia, NZ, SA, Ireland, Scotland), yinz (Pittsburgh, parts of UK) and y’all (US South, West Indies, Alberta).
No committee approved it. Some folks starting using it and, because it filled a need, it spread. Once an old form such as thou has disappeared from a language, it is unlikely to return even if a need for it arises.
Rather, speakers will use the available resources of the living language to innovate. So youse (or yous) is simply a regular “add an ‘s’” plural, y’all is a contraction of the phrase you all, and yinz appears to be a contraction of you ones.
In some places the phrasal you(s) guys is used, and in Kriol, an Aboriginal language of the Northern Territory, the plural yumob comes from you mob.
So, will this very useful innovation become standard? That’s impossible to predict, but we know that many people react negatively to any linguistic innovation, especially one that arises from non-Standard varieties.
The paradox of this prescriptivism is this: most prescriptivists don’t want to see the attrition of a language’s expressivity and nuance. But prescriptivism rarely prevents the disappearance of forms and structures. It didn’t save thou. But what it may hamper is the arrival or spread of innovations.
Prescriptivism doesn’t like to let stuff in, but it’s no good at stopping stuff from falling out.