Leo Rosten, a maven of Yiddish and a man addicted to corny jokes, died Feb. 19. First published in 1937, the novel is widely credited as a classic. Rosten's enduring contribution is his explorations into Yiddish, the language whose survival and vitality he credited to Jewish women and which he learned from his mother. Yiddish is one of the great sources of the distinctive vocabulary of 20th century English.
Obvious words are kibosh, shlep, goy, shmuck, chutzpa, bagel.
At least for the Ashkenazim. Rosten had a habit, not unusual, of excluding Sephardim from his understanding of Jewish history. The Sephardi Ladino dialect was largely excluded from his calculus, unsurprisingly since its influence on modern English is minimal. As for the death of Yiddish, Rosten gave Hitler and the establishment of Israel the bulk of the credit. Because Yiddish was the language of the underclasses, of the illiterate, of the Germans ultimately, it became unpopular.