Hiberno‐English (also sometimes referred to as Irish English) is the dialect of English written and spoken in Ireland (Latin: Hibernia).
English was first brought to Ireland as a result of the Norman invasion of the late 12th century, although during that time the Normans did not speak English, but rather Norman‐French. Initially, it was mainly spoken in an area known as the Pale around Dublin, with Irish spoken throughout the rest of the country. By the Tudor period, the Irish culture and language had regained most of the territory initially lost to the colonists: even in the Pale, "all the common folk… for the most part are of Irish birth, Irish habit, and of Irish language". However, the resumption of English expansion following the Tudor conquest of Ireland saw a revival in use of their language, especially during the plantations. By the mid-19th century, English was the majority language spoken in the country. It has retained this status to the present day, with even those whose first language is Irish usually being fluent in English as well.
Modern English as spoken in Ireland today retains some features showing the influence of the Irish language, such as vocabulary, grammatical structure, and pronunciation. Most of these are more used in the spoken language than in formal written language as used in say the Irish Times, which is much closer to Standard British English, with a few differences in vocabulary. (Wikipedia)