One of the most interesting aspects of Kafka's work is that he wrote in Prussian dialect, not German. Prussian literature is uncommon, at best, as Prussian is thought to be a strict, highly technical language-- the language of engineers. (The difference between Prussian and German is akin to the difference between the English of Nabokov's Lolita and that of the Owner's Manual from a '94 Jeep Wrangler.)
In this regard, Kafka follows an interesting Jewish literary tradition: the oldest Jewish prayers (e.g. Mourner's Kaddish) and literature (e.g. The Old Testament's Song of Songs, aka the Song of Solomon) are written in Aramaic-- a trade language older than Hebrew. The vast bulk of the Jewish contribution to World Literature and Art, prior to WWII and Shoa (aka the Holocaust), was in Yiddish-- a pidgin composed of German, Russian, Polish, Hungarian, Greek, etc. and rendered in the Hebrew character set (just as Aramaic is.) Yiddish was primarily a trade language. What's this all mean? Uncertain-- but certainly an interesting tidbit.
