R' Hirsch and Yiddish

I have been asked the following question and would like to know what others think. The answer provided is my own.
Daniel

Do you know if RSRH knew/spoke Yiddish?

Hmm, interesting question. R' Hirsch, as we know, spoke Hoch Deitch, a high form of German. We know that later individuals, such as R' Bernard Drachman, who translated the 19 letters into English, would not speak Yiddish, as he felt it was a corrupt form of German. R' Hirsch, being very proud of language (not just Lashon Kodesh and German; he was an expert in philology and language - and we have at least two letters that he wrote in English), may have felt the same way. On the other hand, German Yiddish was different than the Eastern European Yiddish. German Yiddish is called Yiddish Deitch and was spoken in Germany. There is a very good chance that R' Hirsch spoke this type of Yiddish and not Eastern European Yiddish. We know that this Yiddish is actually a Bavarian dialect of German.

What about the generations before Hirsch? Did they speak Yiddish in Germany or German? Or let me ask it this way, did Yiddish develop in Germany or outside Germany? It seems from Wiki that Yiddish developed in Germany. This makes sense of course. Children learn the language of their host country. I know children of Olim that speak poor English. When Jews went to Russia, they wouldn't develop Yiddish, a Germanic language just because they might have spoken German. They would have learned Russian. So what happened is that when Jews came to Germany or let's call it the Rhine Valley, they learned German and turned it into Yiddish. When they went to Russia, they went with an intact language that actually changed a bit into Eastern Yiddish. In Germany they spoke Western Yiddish.

After the emancipation most of the Jews of Germany switched to German much as children of Russia immigrants in America switched from Yiddish to English.

However, maybe somebody can tell me if I have this right or wrong.

I spoke with R' Hamburger about this and he said certainly Yiddish was the primary language of German Jewry before the 19th century. It was a Western Yiddish, different from what we tend to hear today - Eastern Yiddish of which there are several varieties.

This is one reason that a German Rav such as the Chasam Sofer could move to Hungary and run a yeshiva there. In Hungary they spoke Yiddish (Hungarian at the time was for gentiles) and he spoke Yiddish.

Yiddish was developed in Germany.

There are extant letters between Rabbiner and Rebbetzin Hirsch in Jüdisch.

Some reformers, such as Abraham Geiger (brother of the Divrei Kehillos) wrote their parents in Jüdisch, despite the Reform tendency to shy away from anything which was not sufficiently assimilated.