Greek has various phrases for different times of day/occasions, but a very polite word for Hello which can be used anytime is Herete.
Adio (soft d) is goodbye acording to the phrase books(but Greek friends say "no,don't say that it means you won't come back" (even after they've heard me sing!).
Where I come from it's "Ow do,our kid?" and "tara a bit" but that's dialect not language!
RtS