...and I'd like to add...
I want people to know, while some of these grammatical errors can be taken as ignorant to those who don't speak that way, I don't think some are at all. The sell/sale and seen/saw thing is totally regional and I think it's about kinship. The old familiar, "You're not (or you ain't) from around here, are you?", thing comes into play. We as humans want to feel accepted/connected. It goes back to tribal times and tribal/territorial is only human. Upper crusties have their own ways of doing the same thing. Somehow when you mispronounce Harvard as Hahvahd or tomato as tomahto it shows you are more educated? Really? They don't have English class in private schools? Cuz I did well in public school somehow and the letter 'r' doesn't sound like an 'h' and when a single consonant follows a vowel it is to be pronounced as a long vowel when in the middle of a word.
I work for a woman brought up all prim and proper. When I mention the Maryland town of Havre De Grace phonically (and the way we here in MD say it) she corrects me with, "It's Hahva dey Grah"*, as if suddenly becoming French for one word. I've said to her, "Well, I'm not French or English. I'm an American from Maryland, it's our town and that's how we say it". She'll say, "Well, my father always corrected people for pronouncing it that way". My reply, "And how did he pronounce Paris or Detroit?".
That's when I make my point. We speak American in this country, just like Australians speak English the way they chose.
Proper English begs for improvement in many ways. What does 'you' mean, one or many people? Both! That's why an hour south of here in VA they say y'all, right here many say you all, an hour north in PA they say yous, and a bit to the west in OH they say you'ins. We are only trying to be more clear to distinguish we are addressing many rather than just one. It really makes a difference at times. I feel totally uncomfortable not saying you all, but when I'm south I might say y'all because I feel I am southern. When I go north or west to OH I don't say it their way because my accent doesn't fit and I like being seen as 'not from around here'.
There are so many ways to speak this language from one area to another. This is the internet and we are all brought together as one where we see these differences. I traveled a lot of this country when I was young and have had lots of time to get used to it all. As long as we know what someone means, it's all good...and colorful! Ain't that right, Jethro? And what say you, Jefferson?
* Do we pronounce it Brett Fahva? Not Favre, either. I guess the proper "French" is pronounced Farve, (kinda like centre pronounced center?) so they would pronounce it Harve I guess.