Irish is given recognition by the Constitution of Ireland as the first official language of the Republic of Ireland (with English being a second official language), despite the limited distribution of fluency among the population of that country. Since the State was founded in the 1920s as the Irish Free State, the Irish Government required a degree of proficiency in Irish for all civil service positions (including postal workers, tax officials, agricultural inspectors, etc.), as well as for employees of state companies (e.g. Aer Lingus, RTÉ, ESB, etc). Proficiency in Irish for entrance to the public service ceased to be a compulsory requirement in 1974, in part through the actions of protest organizations like the Language Freedom Movement. While the requirement was also dropped for wider public service jobs, such as teaching, Irish remains a required subject of study in all schools within the Republic which receive public money. The need for a pass in Leaving Certificate Irish for entry to the Gardaí (police) was dropped in September 2005, although applicants are given lessons in the language during the two years of training. Most official documents of the Irish Government are published in both Irish and English.
There are a number of distinct dialects of Irish. Roughly speaking, the three major dialect areas coincide with the provinces of Munster (Cúige Mumhan), Connacht (Cúige Chonnacht) and Ulster (Cúige Uladh).
The features most unfamiliar to English speakers of the language are the orthography, the initial consonant mutations, the Verb Subject Object word order, and the use of two different forms for "to be". However, initial mutations are found in other Celtic languages as well as in some Italian and Sardinian dialects, as an independent development. They are also found in some West African languages.
The date of introduction of Celtic languages to Ireland is an open question, debated by linguists and archaeologists. The earliest form of the language, Primitive Irish, is found in ogham inscriptions up to about the 4th century AD. After the conversion to Christianity, Old Irish begins to appear as glosses in the margins of Latin manuscripts, beginning in the 6th century, until it gives way in the 10th century to Middle Irish. Modern Irish dates from about the 16th century.