While General Clark was born in a predominantly Jewish neighborhood in New York City, there's no documentation indicating he was fluent in Yiddish or even spoke it at all.
It's important to note that:
* Many Jewish people in the US did not speak Yiddish. While Yiddish was a common language in many Jewish immigrant communities, not everyone was fluent.
* General Clark's background is not solely defined by his place of birth. His family background and personal experiences would have influenced his language skills, not just the neighborhood where he grew up.
Without any confirmed information, it's best to avoid assuming General Clark spoke Yiddish.