Thank you Ms. Orange for your comment on my previous post. I suggest everyone take a look at her (I'm assuming you're a her) site: http://blog.orangederange.com/. I like it.
Anyway, people in the Southern and Central Appalachians in the USA were fairly isolated for a couple of centuries or so. Major river systems passed them by, there were no major roads thru the area until the mid-20th century, and not that many then. I think trains showed up in the early 20th century. So, I think a lot of the language spoken there was to a certain extent, frozen in time. I'm sure it changed over time, but perhaps not as quickly or in the same way. I understood it, though I didnt really speak it that much. My major hold over is I'm constantly saying "I reckon", instead of something like "I guess", or "I think so", but I think that's all over the South, not just the Appalachians. Oh, and of course you all (y'all), tho I always am refering to more than one when I use it, tho it's not always evident.
I think things really started changing with WWII, when hundreds of thousands of people were drafted or joined the military, and traveled to the corners of the earth. What an experience (terrifying or otherwise) that must have been. And then, they started building roads. Here's an example: Highway 80 is now a 4 lane road that running through Knott County Kentucky. When I was growing up, it was a twisty turny mountain highway. Well the twisty turny highway still exists, but its now called 550. When I was growing up, my father's parents house was quite aways off anything like a main road. The road to their place was dirt & creek, and if the creek was up, you didnt get there. The family cemetery was way up on a hill, and I remember walking up a foot path to get there. Well, the "new" highway 80 fixed all that. Where my grandparents lived no longer exists - they piled about 40 feet of dirt on it. A 4 lane road pretty much destroyed their property. The family cemetery that you had to take a foot path to get to & was way up a hill is now right next to a busy highway. Well, it makes a difference - things can happen now that never could before, and the region is more prosperous and is one step closer to being like the rest of the country. The isolation that used to exist really, for the most part, doesnt any more.
Unless you look for it. Get off the main road, and you can find yourself in another world. Its just that the main road isnt so far away anymore.
Anyway, back to language. I read Huckleberry Finn at age 11. I had no trouble understanding the language, and I didnt realize anyone else would. That book is written in 7 different dialects I think, of a section of Missouri in the 1840's or 1850's, from the highest to the lowest echelons of small town society at the time. I understood it all, and didnt think a thing of it. I didnt realize that some people found it almost like a foreign language. My son, who grew up in Maryland, struggled with it. Even if I had not used the language myself, or hadnt really heard it used, I knew what it meant - I don't know how, I just did. When Huck says, "I aint got no truck with no hounds", I knew, at age 11, exactly what he meant. It took me years before I realized that many people had no clue that all he's saying, in a colorful and round about way, is that he likes dogs. They didnt realize all the meanings "truck" can have. And that has to be because of where I grew up, and listening to the older people talk.
I am not any kind of expert in languages, shoot, I took a history of the language course in my senior year of college and it "liked to kilt me". This is just my observations and thoughts.