To explore the principal languages of the Jews in Eastern Europe, this entry includes four articles. The first two treat Hebrew and Yiddish, respectively, from a linguistic perspective, including their historical development, dialects, and status. Planning and Standardization of Yiddish describes the attempts to elevate the status of Yiddish and to standardize its spelling, and the political context of these efforts. Finally, Multilingualism surveys this phenomenon among East European Jews, combining sociolinguistic data with an evaluation of its cultural consequences. For further discussion of Yiddish-language standardization, see Czernowitz Conference. For Hebrew and Yiddish as literary languages, see Hebrew Literature and Yiddish Literature.