I agree that there is a certain ta’am to Yiddish, and I always wished that I could speak and understand it better than I do. (Ich farshtay a bisel, uber nisht zeir gut.) But I have trouble with the schools (in which most students do not come from Yiddish speaking homes) insisting on teitching in Yiddish. I live in a community where ALL the girls schools teitch Chumash in Yiddish through 5th grade, so it’s not like I had a choice where to send my girls. Some of my girls were are not very good at languages, and this really hampered their ability to understand what was being taught, and was a big shtuch to their self-confidence. To be honest, they actually teitch into Yiddish and then English, but for someone who has trouble with languages this can be very disconcerting and is hard to follow along (even if they are not held responsible for the Yiddish).
When I questioned the school’s policy, I was told that this is how Rav ….. held – Rav ….. was niftar over 45 years ago (when Yiddish was still spoken in most homes)! Does anyone bother to ask if this still applies?!
Ironically, when my oldest boy started yeshiva, there were one or two boys yeshivas in the community that teitched straight into English, and my husband insisted on sending him to one of those, based on Rav Yaakov ztz”l’s opinion that talmidim should be taught in the language they are most comfortable in. (I was actually worried that for boys it is necessary to learn Yiddish, but B”H my son is now in Bais Medrash in a very prominent yeshivah, and his love of learning was not compromised by having to struggle to understand what was being taught.)
I think it is a very nice idea to teach Yiddish, but it should be taught as a separate subject, so that if a student has trouble with it, it does not interfere with their comprehension of Chumash or Gemara.