I am now completing research supported by NSF and NEH that is mapping changes in the English language through all of North America, for both mainstream and minority communities.
Language changes very fast.
Words have a genealogy and it's easier to trace the evolution of a single word than the evolution of a language.
The extraordinary thing about new words is that probably only about one per cent of them are new. Most are old words revived and adapted.
New words can spread like wildfire thanks to social media - you only have to look at 'mansplaining' and 'milkshake duck' to see language evolution at work - so why not old ones too?
I believe every change any word has undergone probably originated in ignorance.
All words have life cycles.
I can take a phrase that's rarely heard/Flip it - now it's a daily word
I would say 'woman' used to be a noun, and now it is a noun and also an adjective. And words change their functions in that way. It's one of the most common phenomena about words. They start as one thing, and they end up as something else.
What is slang in one age sometimes goes into the vocabulary of the purist in the next.
