In Part I, Michael has Fabrizzio translate for him to Apollonia's father. I realise FFC had him do this because Al Pacino could not talk Sicilian. But earlier in the film he talks Italian with Sollozzo. Are the two languages spoken in this scene different (ie. are Sicilian and Italian two different languages?) It just seems odd that Pacino would trouble himself to learn so much Italian for the Sollozzo scene nd then speak English for the Thunderbolt scene.
And then in Part II, when Fanucci comes into Abbandando's Grocery, why does Genco sart to explain to Vito what is happening? Can't Vito hear or understand what Fanucci is saying? Are there different dialects within the Sicilian language?

Any insight would be much appreciated. THanks in advance.
Mick