יידיש
Yiddish
Ocean Hill-Brownsville +1Yiddish, the principal mother tongue of European (or Ashkenazi) Jews, has likely been spoken in the city since the 17th century, but large waves of speakers first arrived in the 19th century: initially German Jews, some of whom apparently still used now largely moribund Western Yiddish, and later large numbers of speakers of all varieties of Eastern Yiddish from across Yiddish-speaking Eastern Europe. By the early 20th century, New York City had become the largest Yiddish-speaking center in the world, with mass media, theater, and other institutions to match.
A
fter the Lower East Side and Harlem, Brooklyn became the next major destination for working-class Yiddish-speaking Jews in the early 20th century, with Brownsville and East New York becoming home to hundreds of thousands. While this community had largely moved away by the 1950s, Yiddish speakers have continued to live throughout the borough, with large numbers in Williamsburg, Crown Heights, Flatbush, and elsewhere.
Note that the language above may be used throughout the New York area — this is just one significant site.