I have met some people from The U.K. and they seem to be well read people, but they use some pronouns incorreclty like "You was" instead of You were. In the U.S. some African-Americans also say it, and I know that in the 80s and before those years was normal for some people.
I´ve read that a long time ago people used to say it but I wonder why new generations nowadays still say it?
- alecoibaNovember 2019
Also worth noting: There are "All White" communities in The United States, principally portions of the eastern ;portion of the USA's mountain range called "Appalachia", extending from (the state of Virginia in the north to parts of the state of Georgia in the south, where the dialect of English spoken daily by many of the inhabitants of these regions would be utterly incomprehensible to most non-native English learners @ all levels; these dialects, though they are in some senses closely related to so-called Black English, are even quite difficult for someone like me, a native English speaker who was raised in a part of Chicago comprised of (roughly) 90% African-Americans throughout the 60s, 70s, and still today in 2019. And still, I have travelled throughout "America's South", alone and with others, and have visited portions of West Virginia, Tennessee, and The Carolinas @ which I had a GREAT DEAL of difficulty understanding the "speech" of the locals. This is also true of certain areas within and especially just outside of New Orleans, where "Creole" - a mixture of English, French, Spanish, and Native American (i.e., Indian) dialects are spoken. If one drives out to the rural area around, say, Lafayette, Louisiana, one will be hard-pressed to understand much of what the locals are speaking. The "dialect" one typically hears of USA/American English in Hollywood (TV and/or film) productions and as spoken @ US-sourced news and information services IS NOT reflective of the great variety of dialects that still persist in many regions of the USA.
Again, hearing an odd phrasing of the verb "to be", as in your example, barely scratches the surface of what would be grammatically challenging, and most likely impossible to decipher, "English as it is spoken in America (USA)".
English, right or wrong, for better or worse, is a VERY FLUID language that is, owing to myriad cultural influences and the influx of migrants, is changing every day! It is EASILY the most fluid language on planet Earth.
And as far as this emanating from The 80s, no my friend, it dates back to a much earlier time in (US) American cultural history, but the rise of popularity coincides with the spread of Ebonics via the worldwide domination of Rap Music and related elements, thus a phenomenon that first spread in The States circa 1990 and, later, circa 2000+, to the rest of the planet. Yo dawg Rappin' be phat, y'all dig?
The incorrect use of the verb "to be" is very commonplace among (native) English speakers in certain Black communities in The United States; there's even a "special term" used to define this phenomenon: Ebonics.
Thus, corruptions of the verb "to be" in the past, present, and future tenses is very typical. A few examples:
1. "You was" (= you were)
2. "You be" (= you are)
3. "You be" (= you will be -- note utter lack of future tense correct form - very typical among Black English users)
Regarding the "UK" users you have heard (mis)use the past tense of the verb "to be", are you sure their misuse of the past tense of "to be" wasn't a deliberate attempt to "sound street", i.e., they were speaking in imitation of, say, US-based Rap Music, in which one will encounter myriad infractions of (correct) English grammatical rules? Mis-use of the verb "to be" is only the tip of the iceberg! It IS possible that the Brits you encountered were imitating "lower class" British usage, most notably the so-called "Cockney" dialect of East End London, a subtle element perhaps "lost" on a non-native English user.
Anyway, Black English, or Ebonics, has become quite popular in The States and perhaps as well in other native English speaking countries, and thus you might hear it more often that you realize, yo. (yo = "right" or "ok" and is derived from Ebonics)