As of 1939 Yiddish was spoken by 10 million people.
Professor Ruth Wisse sees Yiddish as a language of the youth, with vitality; inventing Jewish modernity. One of the values of studying Yiddish is to understand the culture of America, much of which stemmed from the rich folk culture of Yiddish. Yiddish stemmed from a society that was isolated from the surrounding cultures. Upon arrival in America, most Jews encouraged their children to blend into the prevailing American success story and as a result Yiddish has practically disapperared.