My mothers first language was yiddish (She hasnt spoken it in years as she has nobody to speak it to) and it was my grandmothers as well. I can somewhat understand it if spoken loudly , slowly and clearly (Im sure it wouldnt take too long to be up to speed as I used to hear it alot when I was smaller) , so to say I have a problem with yiddish speakers is just wrong.
I understand spanish and can speak it and if anyone tries the spanish trick on me, they immediately stop