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Good read. "Where you at?" made me cringe!
Interesting read! It's important for languages and rules to breathe and evolve with the people speaking it. Rules that make speech harder or "more elite" need to be adjusted, and I'm glad this one is finally getting the attention/adjustment it needs.
I see the preposition at the end of a sentence all the time in depos. I guess that is how we talk - informally. Perhaps in the UK it is less prevalent and more formal?