[anghyflawn]

I'm not sure why you are being downvoted, but this is at best only partially correct. Yiddish was supported along with pretty much all minority languages in the 1920s and early 1930s, but this support also ceased when the minority support policy was reversed (with token remnants such as the Yiddish being an official language in the Jewish "homeland" in the Far East). Following WWII and postwar persecutions of Jews Yiddish all but stopped being transferred from parents to children in the USSR. I remember how happy my grandfather (born 1928) was when it became possible to embrace one's Yiddish heritage again in the late 1980s); but he did not teach the language to his children.