> one current top show in France with French people on it got french subtitles
One friend of mine once had to translate English-to-English in France. A French policeman or taxi driver or something knew English as a second language. My friend is from New Jersey and sounds like what I might call CNN English (is there a name for roughly "unaccented" Northeast/West Coast/DC English?). The other person he was with had a thick Alabama accent. The Frenchman could not understand what he said directly, but could understand it when repeated by the New Jerseyan.
I think "General American English" is the term for that.
> (is there a name for roughly "unaccented" Northeast/West Coast/DC English?)
General American English.
Although it's traditionally much more common among white people in the western half of the country. People on the east coast, as well as black people everywhere, traditionally have distinctive accents (though these are fading over time, and many people from either group now speak pure General American).
Like that scene in Hot Fuzz where they go out to talk to the farmer about cutting his neighbor's hedge, and they need a translator for the translator