YIDDISH

Yiddish is a hybrid language that has been spoken by the Ashkenazic Jews of eastern and central Europe since the Middle Ages. Yiddish is mostly German in its linguistic structure and vocabulary, but it is written in Hebrew characters. Originally, Hebrew words pertaining to Jewish religious life were added to German. Later, when the bulk of European Jewry moved eastward, Slavic words were added. Yiddish today is about 85 percent German, 10 percent Hebrew, 5 percent Slavic, with traces of Romanian, French, and other elements.

Yiddish originated in the Rhineland cities of Germany in the early Middle Ages (c.1000-1250). The first recognizable Yiddish texts date from the 14th century. Yiddish spread all over Europe over the next few centuries. More Jews have spoken Yiddish than any other language. Prior to the Holocaust, Yiddish-speakers accounted for 75 percent of world Jewry, or about 11 million people. During the Holocaust, about 75 percent of the world's Yiddish speakers were killed. Today, Yiddish is spoken by about 4 million Jews, located primarily in Argentina, Canada, France, Israel, Mexico, Romania, and the United States.

Source: Lisa Katz on About.com