Irish language (standard: Gaeilge,Munster dialect: Gaoluinn, Ulster dialect: Gaeilic) is the indigenous language of Ireland, until the Irish Potato Famine (in Irish, an Drochshaol, "the Bad Life" or an Gorta Mór "the Great Hunger") of the 1830's spoken by a majority of the inhabitants of the island of Ireland. It is closely related to Scottish Gaelic and Manx (in the Isle of Man), which are, historically speaking, dialects of Irish. These two languages are even, to some extent, intelligible to an Irish speaker: as long as there were dialects of Irish spoken in what is now the statelet of Northern Ireland, these were actually in between today's Irish and Scots Gaelic. The last native speakers of this Irish lived in the Glens of Antrim, in Rathlin Island, and in South Armagh.

Living dialects of Irish are roughly divided into three main groups: Munster Irish, Connacht Irish, and Ulster Irish. In Connacht, there is a finer distinction between the main group (the dialects of Connemara, Aran Islands, and Tourmakeady in southern Mayo) and the Northern Mayo Irish, which shows some affinities with Ulster Irish, especially in vocabulary.

Among the dialects spoken today, those of Donegal (this northern county is in historical Ulster, but it does not belong to Northern Ireland, politically) and Connemara-Aran Islands are the most viable. However, Munster Irish (which means, above all, Kerry Irish, although there are smaller pockets of Irish speakers in County Cork, in Cape Clear, and in County Waterford) has strongly influenced the official standard (and even more the official practice) due to the prestige of Munster literature in school (above all the memoirs of Peig Sayers, Tomás Ó Criomhthain, and Muiris Ó Súilleabháin from Kerry, as well as the writings by the founder of modern Irish literature, Peadar Ua Laoghaire or Peter O'Leary, from County Cork, such as the folkloristic novel Séadna and the autobiography Mo Scéal Féin, "My Own Story"). Even the nationalist fighter Padraig Pearse or Pádraig Mac Piarais, although not a native speaker, contributed with well-written and linguistically superb stories and poems to the literary revival in Irish.

The official standard as used today came about in the end of the 1940's; the reform of the written language, until then based upon the classical orthography of the sixteenth century, was long overdue, but as there was no political will to impose a reformed orthography, the chief translator of the state simply issued guidelines of his own, which were widely adopted as a standard. However, this standard - in Irish, Caighdeán - was just a compromise anyway, and it has been severely criticised by native speakers and dialect enthusiasts. Especially the prolific rural prose writer Séamus "Máire" Ó Grianna (brother of Seosamh Mac Grianna) from Donegal was very critical of the new standard.

Irish might not yet be safe from extinction, but it is not going to die tomorrow, next week, or next year, and good Irish is still spoken and written in Ireland. While much of the literature written today is linguistically deficient, the writers having learnt Irish as a second language, modern Irish literature boasts of some truly distinguished writers and works, above all the great modern classics Máirtín Ó Cadhain and Seosamh Mac Grianna. Another important writer was Pádraic Ó Conaire, the first modern prose-writer in the language. Even today, there are native speakers writing in the language, such as the poet Nuala Ní Dhomhnaill, the biographer and sports journalist Pádraig Ó Baoighill, the ex-emigrant to America Maidhc Dainín Ó Sé, or the ambitious, intellectual prose writer Pádraig Ó Cíobháin. The revolt of the Sixties was in many ways incarnated in Caitlín Maude, the gifted poet, playwright and orator, who died relatively young in 1981. Many important Irish writers have written in both languages, such as the journalist and political commentator Breandán Ó hEithir, a native speaker, his elder relative Liam O'Flaherty, the humorist Flann O'Brien (aka Myles na gCopaleen), and the playwright Brendan Behan (Breandán Ó Beacháin).

The student of Irish will probably be rather disconcerted by two grammatical features above all else: the word-initial mutations in Celtic languages and the use of two different verbs "to be", which are not interchangeable (although this latter feature is also found in Spanish). However, on the other hand, Irish was drawn into the orbit of Latin much nearer than many other European languages, because Christianity entered Ireland so early. This means that even the core vocabulary of the language is replete with early Latin loan-words. Of course, the language has been, and is, influenced by English; but, above all, Irish and English have been subject to similarforeign influences, which adds to the common ground. For example, both languages have, at the same time, assimilated quite a bit of Scandinavian and Norman French borrowings: anchor/ancaire, advantage/buntáiste, giúistís/justice and many other well-established cognates witness the shared history of the two languages.