Does anyone have a date for the writing of the words (and music) of the song?
I'd guess (from Padge Keogh Jr's age), that his father was born around 1900-10, which means the lyrics would've been composed some time in the mid-20th Century. I'm assuming that PT Kinsella's melody was composed earlier.
I'm studying the Gaelic/Irish of Co. Wexford. Despite Norman influences mentioned by Mariner, there were 79 native irish-speakers over 70 y.o. in Co. Wexford in the 1911 census, with small clusters around Fethard, and Kilcomb (near Comolin) - Royal Irish Academy survey by Garret Fitzgerald (1984). The English of Co. Wexford is replete with extant Irish words - ever-diminishing due to globalised mass media.
Garmanach agus ceoilteoir