Yeshivish (Yiddish: ישיביש), also known as Yeshiva English or "Yeshivisheh Shprach", is a sociolect of English spoken by Yeshiva students and other Jews with a strong connection to the Orthodox Yeshiva world. Yeshivish may also refer to non-hasidic ultra-orthodox Jews.
Only a few serious studies have been written about Yeshivish. The first is a master's thesis by Steven Ray Goldfarb (University of Texas at El Paso, 1979) called "A Sampling of Lexical Items in Yeshiva English." The work lists, defines, and provides examples for nearly 250 Yeshivish words and phrases. The second, more comprehensive work is Frumspeak: The First Dictionary of Yeshivish by Chaim Weiser. Weiser (1995) maintains that Yeshivish is not a pidgin, creole, or an independent language, nor is it precisely a jargon. Baumel (2006) following Weiser notes that Yeshivish differs from English in three ways.
Benor (2012) offers a detailed list of distinctive features used in Yeshivish. Katz describes it in Words on Fire: the Unfinished Story of Yiddish (2004) as a "new dialect of English", which is "taking over as the vernacular in everyday life in some ... circles in America and elsewhere". Heilman (2006) and others consider code-switching a part of Yeshivish. Though Kaye (1991) would exclude English speakers in the context of a Yeshiva, studying the Talmud, from code-switching where he considers the terms "Yiddish English" or "Yiddishized English" ("= Yinglish") may be more appropriate.
The English variant of Yeshivish consists of grammatical irregularities borrowed from Yiddish, and a vocabulary consisting of Yiddish, Rabbinic Hebrew, Talmudic Aramaic, and sometimes Modern Hebrew. The speaker will use those terms instead of their English counterpart, either because of cultural affinity, or lack of the appropriate English term.