I've been learning Latin bit by bit using Orberg's Lingua Latina. At the end of chapter 6 there's the following sentence:
Verba Medi a Lydia laeta audiuntur
As far as I can understand it concerns Lydia hearing Medus' words and being happy. My confusion however is why Medus ends as Medi (which I think is genitive) but verba ends in 'a' and not verbis. A sentence prior to this one says this:
Lydia verbis Medi delactatur eumque salutat
Which I translated as 'Medus' words delight Lydia and she greets him'. Why is one sentence 'verbis' and the other 'verba'. Am I completely mis-translating it? Can someone shed some light on this?