The two things I hear a lot are:
“You want?” This is as opposed to “Would you like this *insert thing here*?”
“Does your mommy let?” This is as opposed to “Does your mommy allow you to do this?”
I don’t know if I should bother correcting people when I hear this. Conversely, I can barely get by in Yiddish, so who am I to judge?
By the way, I’ve made such an effort to not say “I’m eating by the So-and-so’s this Shabbos.” I now say “I’m eating with…” because this thread has enlightened me. 🙂