quote:so...what exactly is the difference between roimh and sula?
I've heard "déanaim an chocaireacht sula n-ith mé dinnéar" and "ithim bricfeasta roimh an obair"
what's the difference?
As Lars said, the difference is simply that roimh is a preposition (so it can't be used before a conjugated verb, but only before nouns or verbal nouns) and sula is a conjunction... so normally it can only be used before conjugated verbs.
So, you say : sula n-ithim but not *roimh ithim
and roimh an obair, not *sula an obair
quote:Beirigh at t-uisce sular n-ólann tú é (nó is duit is measa)
little typos: an t-uisce; sula n-ólann