An Italian Yiddish was never in the cards, as the case of “Judeo-Mantuan” makes clear, because Jews were more closely integrated into Italian society than they were in Eastern Europe.
Alter Leyb Robinson and his friend, Shabbos.
Separated by a common language?
The many hypothesized sources for the saying, “To have butter on one’s head.”
From the Cairo Genizah.
Blame the Bible.
And their literary history.
The process results from, in equal measure, Jewish separateness and Jewish assimilation.