Yiddish isn't an official language of any country. Jews from
various Eastern European countries, mainly Germany, Russia, Poland,
and the Ukraine spoke/speak Yiddish.
Yiddish is an Eastern European Jewish language that was spoken in several languages. The original language was primarily High German with some Hebrew and Aramaic and written using the Hebrew alphabet. However, there are different Yiddish dialects today: German, Russian, Polish, and Ukranian.