On the eve of World War II , there were 11 to 13 million Yiddish speakers . The Holocaust , however , led to a dramatic , sudden decline in the use of Yiddish , as the extensive Jewish communities , both secular and religious , that used Yiddish in their day-to-day life , were largely destroyed . Around five million of those killed — 85 percent of the Jews who died in the Holocaust — were speakers of Yiddish . Although millions of Yiddish speakers survived the war ( including nearly all Yiddish speakers in the Americas ) , further assimilation in countries such as the United States and the Soviet Union , along with the strictly monolingual stance of the Zionist movement , led to a decline in the use of Eastern Yiddish . However , the number of speakers within the widely dispersed Haredi ( mainly Hasidic ) communities is now increasing . Although used in various countries , Yiddish has attained official recognition as a minority language only in Moldova , Bosnia and Herzegovina , the Netherlands , and Sweden
The Holocaust
The Holocaust
Yiddish