I've been doing Irish for quite a while but... I still couldn't find a relation between what is written and jow it is pronounced, at least a geat part of the time. (Just for example roghnaíonn any normal person would expect to see a "a" sound...) Is there any pronounciation rule?
...well, the 'í' is accented, so you'd expect to pronounce that... and if the 'í' is pronounced, the 'a' that precedes it would be there to bracket the 'n'... however I agree, it can be a challenge.