I grew up in a home where Yiddish was spoken as well as English so I did not encounter much difficulty in understanding Taitch. The problem these days is that most American born Rebbis (except those in Chassidishe communities) don’t really speak Yiddish very well so most of what they teach in is “Yinglish” (sometimes called Yeshivish). I maintain that Instruction should be in English. English has, by far, the largest and most nuanced vocabulary of any language, enabling precise translation of the most complicated concepts. Of course, the problem with that is that most American born Rebbis don’t speak English very well either.
P.S. RMF maintained that all Ashkenazi Jews should learn Yiddish as a Minhag Kadosh.