As a mixture of medieval German, Hebrew and other languages used in countries where Ashkenazim have lived, Yiddish was spoken by millions of Jews all over the world for nearly a thousand years. Although no longer used in everyday life, Yiddish remains as one of the major elements of the Ashkenazi culture.
Consisting of Eastern and Western dialects, Yiddish is made mainly of German words. Western Yiddish was predominately spoken in Germany, Switzerland, the Netherlands, France and Hungary, while Eastern Yiddish was used in Central and Eastern Europe. And of course, in Turkey too.
In the beginning of the 20th century, the number of Yiddish speakers was about eleven million. Today, this number has dropped to tens of thousands. However, thanks to the cultural mobility of Ashkenazim, many Yiddish words continue to live in European languages.
Frayman, Erdal vd. Yüksekkaldırım’da Yüzyıllık Bir Sinagog Aşkenazlar (A Century-old Synagogue in Yüksekkaldırım Ashenazim). Tiryaki Publishing, Istanbul, 2000, p. 43-44.