Complex sentence: Although there is evidence of Telugu literature before Nannaya, he is given the epithet "Aadi Kavi" ("the first poet") because he was the first to establish a formal grammar of written Telugu.
Split into simpler sentences: Although there is evidence of Telugu literature before Nannaya, he is given the epithet "Aadi Kavi" ("the first poet"). Nannaya was the first to establish a formal grammar of written Telugu.