Italians don't sound like this; it's very much a regional microculture unique to the locals. I marched in the annual Greektown Independence Day parade and an ambassador from Greece gave a short speech, and the master of ceremonies thanked him and said "I even understood some of it" to the laughter of the crowd, because "American Greek" and actual Greek spoken by Greeks aren't identical. A friend of the family visited Greece and found out how many "American Greek" words there really are - he called a stamp "estampa," in Greece its called "grammatósimo," literally "letter sign" or "letter mark." He asked directions to the train station with the word "traino," which actually *is* used in modern Greek but not in that context; the word he needed in that conversation was "sidi̱ródromos," for railway, which literally translates as "iron road." Hilariously, I learned how these words arise from the Belgian side of my family. My mother once asked my great-grandmother how to say "guinea pig" in Flemish and she replied "Ratta." "No, grandma, guinea pigs do't have tails like rats." She shrugged and said "ratta without a tail!" (Incidentally, this is why you can get so far in Japan by adding an "o" to the end of many English words. My Japanese bros understand.) But yeah, if you want to LARP as fresh off the boat you'd have to make an especial effort and/or visit the old motherland first, and you'd stand out even in your own diaspora community in the US.