I'm using Micheal O Siadhail's Learning Irish, an old 80s edition my mom's had lying around the house my whole life (and sometime this week I'll have a tape player so I can start fighting with the pronunciation, too -- spelling and pronunciation aren't even kissing cousins in Irish, are they?), but I don't think I've hit prepositional pronouns yet.

Dialects are such handy things, aren't they? You can blame all sorts of nonsense on them...