Frasier

Upon hearing that Frasier was brought up in Seattle, Helen asks if he was "bar mitzvah-ed" there. Although her wording is consistent with a common misconception, the term "bar mitzvah" literally means "son of the commandments" and should only be used as a noun - either to refer to the boy who has reached the age of thirteen, or the ceremony that marks the occasion. Using the term as a verb (i.e. bar mitzvah-ed), as Helen does, is grammatically incorrect.

Roz says that she had forgotten that Frederick was "half-Jewish". Although this is a common expression, according to Jewish Law, one cannot be half-Jewish. If one's mother is Jewish, they are Jewish; if she isn't, they are not.

In describing his "bar mitzvah" to Mrs. Moskowitz, Frasier mentions that his mohel (pronounced moyl) was present. Even if Frasier didn't have a Jewish wife and a son who was raised Jewish, it is highly unlikely that a man of his education wouldn't know what a mohel was.