When gamemastering, I like to have the characters be very animative and dynamic. Part of giving them a personality is to give them a particular way of speaking. I like to give them an accent, according to what part of JERA that they are from. Gamemasters vary with how talented that they are in impersonation and voice manipulation, but the following may be a nice guide. Also, if in my short stories or other places there is conversation, knowing what people sound like from various areas may help you idendify where they come from. Basically, mentally label this section "VERY optional".

Region/Group Earth equivalent sounding slang
Upper Crust of larger cities (Grunburg, Alexander) British Accent (Grunburg elite have strongest accent)
Southern Asterland Islands Jamaican Slang/Accent
Eastlands (Trannor Kingdom, for example) Scottish (highlander)
Asterland Kingdom American Accent/No slang
Punks Strong Urban American Slang/Accent
Northern Asterland Regions German Accent
High Elves French Accent
Desert Humans/Humanoids Western Slang (ala John Wayne)
Innlandstadt/Mauern Southern Drawl
Felann Empire Lisping/Slurring