Nan,
Can you enlighten me on the irregularity of pronunciation among Jewish bearers of surnames with the element -stein (stone)?
Supposedly Yiddish derived from Middle High German, and a high percentage of Ashkenazi Jews bear German surnames. And German is one of the most regular major languages in pronunciation.
So...why the variable pronunciation of -stein as "stine" and "steen"? Zum Beispiel (e.g.), we have Ben Stein (stine), but John Feinstein (finesteen). In the latter, why not "finestine" or "feensteen"? Is there an unwritten rule to this? (Come to think of it, what Jewish mother names her kid "John"?)
Did the "steen" transformation perhaps originate in the WW I era, when bearers of Teutonic-sounding names changed their sound to something less Boche? Viz., Battenberg => Mountbatten, both meaning "group of useless parasites".
Oy, so many questions...
Daividh