Somhairle Óg wrote:
Dublin city was never an Irish speaking city, it was founded as a Norse speaking city, which although began to become Gaelicisised to some extent for a couple of centuries by the influence of the surrounding Gael's, by the 13th century English has displaced both languages in the City. County Dublin, and most of the surrounding counties, would have been English speaking by John Carpenter's time, with a few pockets here and there surviving. Carpenter got his Irish from an Irish speaking school and was probably influenced by a mixture of dialects, Tadhg Ó Neachtain himself being from Roscommon. His writing was probably based upon the scholarly standard given that Ó Neachtain himself was from a bardic family, a tradition on its deathbed at the time. This standard bore little relation to the average man's spoken Irish, the written word of the poet, the priest or the scholar would have been alien to them, I was one told by somebody that the Irish of this class was equidistant to the Queen on England's English vs a Dubliner's English today, but multiplied many times.
Im not trying to be a pain here but just from what iv read and what we did in college i wouldnt say Irish was displaced by the 13th cent, It was thought the situation was bad enough regarding Gaelic customs and language that the Crwon felt the need to put together the Statutes of Kilkenny in the mid 14th cent and even later in the Tudor period that even in the Pale itself ‘all the common folk … for the most part are of Irish birth, Irish habit and of [the] Irish language’