I think that's because in the original Irish lyrics, the song gets a bit more intense than what Celtic Woman likes. However, from the Bean Phaidin translation that I read, it seems Celtic Woman's English lyrics stay fairly true to the original Irish-lyric story. And the parts they do sing in Irish are actually the correct verses (from what I could keep up with): Eabha's first verse, all in Irish, declares that she'd go to Galway with Phaidin and return home with him. Then Susan and Mairead both join in with their English lyrics. Then when Eabha sings in Irish again in the 4th(?) verse, she sings what is essentially a repeat of what Mairead C sang in the 3rd verse. The last verse, after the drum crescendo, is all in Irish and is true to the original lyrics. And it basically says, I hope Phaidin's wife breaks her legs and dies.
So my takeaway from this song is basically this: NEVER come between an Irish girl and her man!
