Italian-Americans were somewhat isolated by ethnicity during their first century here, and some old linguistic ways have been carried down.
I had some friends visit me from Italy when I was living in an Italian neighborhood and studying Italian language for an upcoming trip to Italy. My visitors spoke no English, and several of the Italian-American neighbors came around, excited to see visitors from Italy and trying to trot out their Italian words and phrases. After they left, the visitors told me in Italian, "I hope you are not trying to learn Italian from them; their accents are cosi brutti (so terrible)."
Thanks!