There are only a few remnants of Irish in modern Irish English. Imperial Britain forced English and prohibited Gaelic.
Go raibh míle maith agat in generous translation...
Bog Restroom, loo, the jacks
Bóithrín Small roadway; diminutive form of bóthar (road.)
Craic (pronounced "crack," and often spelled so) An idiomatic term for describing experience in various ways: "great craic," "what's the craic?," "how's the craic?"
Crúibín (pronounced "crew bean") Pig's foot. The term "crew beans" might sound like a euphemism, but it's not.
Fáilte Welcome. Used in tourism and on doormats.
Gaeltacht a political-science delineation of areas in which Irish is an important language in daily life. "The Gaeltacht" refers to the Gaelic-speaking whole although its components are divided into small enclaves, mostly in the west.
Permission to go use the toilet...
Omadhaun (n.) Fool
Póg mo thóin Kiss my ass.
Poitín A beverage distilled from one of several accepted ingredients.
Shillelagh Traditional walking stick. Normal use of the term involves sale to naïve American tourists.
Sláinte "Cheers" (over a drink.) Literally, "health."
Sliotar (pronounced "slitter") The small hard ball used in the Gaelic sport hurling and the women's equivalent, camogie.
Tuig (pronounced "twig") To grasp, to comprehend.