My version

1) AFAIK American English has three main dialect groups, New England,
Southern and Standard. On a map, Standard looks like it fanned out of
New York, like smoke from a smokestack, with the two other dialects on
the side, with the old British colonial centers Boston and Virginia,
emphasizing the role of those ports as entry points for later (New
York) and early immigration. New York was originally Dutch speaking.
Those are the sociological facts. There is no way that would not have
influenced the phonology of Standard American. AFAIK no one ever
looked at the question from this angle.

2) If one uses the standard method of locating the origin of a
language family on Romance, you would point to Sardinia, since that
language is the most conservative. The various Italic languages have
left no trace in Italian dialects AFAIK. This homogenization of
Italian dialects, I think, goes back to two varieties of Late Latin,
Christian Latin on a Greek substrate, from the Greek-speaking
immigrants from the east, and 'Barracks Latin' on a
Germanic/Celtic/NWB(?) substrate. Those are the sociological facts.
There is no way those substrates can't have influenced Romance. AFAIK
no one ever looked at the question from this angle.


Torsten