Yiddish was the everyday language spoken by most Central and East European Jews during the last millennium. As a result of the extreme loss of speakers during the Holocaust, subsequent geographic dispersal, and lack of institutional support, Yiddish is now an endangered language. Yet it continues to be a native and daily language for Haredi (strictly Orthodox) Jews, who live in close-knit communities worldwide. We have conducted the first study of the linguistic characteristics of the Yiddish spoken in the community in London’s Stamford Hill. While Krogh (in: Aptroot, Aptroot et al. (eds.) Leket: Yiddish studies today, Düsseldorf University Press, Düsseldorf, pp 483–506, 2012), Assouline (in: Aptroot, Hansen (eds.) Yiddish language structures, De Gruyter Mouton, Berlin, pp 39–62, 2014), and Sadock and Masor (J Jew Lang 6(1):89–110, 2018), investigating other Hasidic Yiddish-speaking communities, observe what they describe as morphological syncretism, in this paper we defend the claim that present-day Stamford Hill Hasidic Yiddish lacks morphological case and gender completely. We demonstrate that loss of morphological case and gender is the result of substantial language change over the course of two generations: while the case and gender system of the spoken medium was already beginning to undergo morphological syncretism and show some variation prior to World War II, case and gender distinctions were clearly present in the mental grammar of both Hasidic and non-Hasidic speakers of the relevant Yiddish dialects at that stage. We conclude the paper by identifying some of the language-internal, sociolinguistic and historical factors that have contributed to such rapid and pervasive language change, and compare the developments in Stamford Hill Hasidic Yiddish to those of minority German dialects in North America.

意第绪语是上个千年大多数中欧和东欧犹太人使用的日常语言。由于大屠杀期间使用者的极度流失、随后的地理分散以及缺乏机构支持，意第绪语现已成为一种濒临灭绝的语言。然而，它仍然是生活在世界各地紧密联系的社区中的正统派（严格的正统派）犹太人的母语和日常语言。我们对伦敦斯坦福山社区中意第绪语的语言特征进行了首次研究。 Krogh（见：Aptroot，Aptroot 等人（编）Leket：今天的意第绪语研究，杜塞尔多夫大学出版社，杜塞尔多夫，第 483-506 页，2012），Assouline（见：Aptroot，Hansen（编）意第绪语语言结构， De Gruyter Mouton，柏林，第 39-62 页，2014），以及 Sadock 和 Masor（J Jew Lang 6(1):89-110, 2018），调查其他哈西德意第绪语社区，观察他们所描述的形态融合，在本文中，我们捍卫了当今斯坦福山哈西德意第绪语完全缺乏形态格和性别的说法。我们证明，形态格和性别的丧失是两代人中语言发生重大变化的结果：虽然口头媒介的格和性别系统在第二次世界大战之前就已经开始经历形态融合并表现出一些变化，在那个阶段，使用相关意第绪语方言的哈西德派和非哈西德派人士的心理语法中都清楚地存在格和性别的区别。我们通过确定导致如此快速和普遍的语言变化的一些语言内部、社会语言学和历史因素来总结本文，并将斯坦福山哈西德意第绪语的发展与北美少数民族德国方言的发展进行比较。