Irish & Constitution
Status of Language
Article 8 of the Constitution provides that the Irish language as the national language is the first official language. The English language is recognised as the second official language.
Provision may, however, be made by law for the exclusive use of either of the said languages for any one or more official purposes, either throughout the State or in any part of it.
A litigant is entitled to use his native language to present a court case. Considerations of natural justice apply, and he may not impose his choice of language on the other party. There have been a number of challenges over the years to use of the Irish language in official contexts in court, in statutes and equivalent documentation.
Criminal Cases
Issues have been raised as to whether a person has a right to use Irish in criminal proceedings. The courts have stated that it is a requirement of natural justice, particularly in a criminal trial that the witness should be allowed to give evidence in the language, which is his vernacular language, whether English or Irish or indeed any other language.
If the language is not known to members of the court, a means of interpreting the language to the judge and or jury if appropriate, and also in the case of evidence, to the prisoner should be provided.
In an early case the court held that the Irish language being the vernacular of the witnesses and the parties in the case, it followed that whether it is the vernacular of a particular citizen or not, if he is competent to use the language, he is entitled to do so.
Civil Cases
Since the Constitution, the issue of the use of Irish in judicial proceedings has been considered in a number of other cases. A party may be entitled to give his evidence in Irish even in places where English is spoken language. He is not however entitled to demand the entire proceedings should be conducted in Irish, even in districts where it is generally spoken.
A challenge was made to a prosecution conducted in English, where the judge was not competent to understand the evidence in Irish without the aid of an interpreter. The provision in the Court of Justice Act which impose a general duty that justices assigned to districts which included an area where Irish language is spoken should possess knowledge of the Irish language as would enable him to dispense with the assistance of an interpreter, was invoked.
The court, however, held that although the witness may give his evidence in Irish, there was no requirement that the judge hear the case without the assistance of an interpreter. Further cases confirm the rights of litigants to use Irish in the conduct of a case including, the cross examination of witnesses.
Limits to Rights
A party claimed a right to cross examine other witnesses in Ireland which the EAT rejected on the basis that he understood English perfectly well and was wasting the Tribunals in time. The  High Court confirmed there was a constitutional right to conduct the examination or cross-examination through Irish if he wished and that  his ability to speak English or otherwise was not a matter for the court. He pointed out that the legislature had not prescribed limitations in this regard.
The litigant cannot decide what language other parties to litigation must use. It includes furnishing of legal documents in the proceedings unless failure to do so would lead to breach of natural justice. In broad terms, either language might be used unless provision is made by law that one language only is required.
Where the defendant is familiar with both languages, he cannot insist on being served an Irish version of a summons. A prosecutor may use an English language version of a summons in the Gaeltacht if he wishes and there is no obligation under either the ordinary law or the Constitution to provide an Irish version even where requested.
The court did not rule on the case where the defendant did not understand the language, but indicated general principles of natural justice would require that the summons be served in English or Irish as appropriate. The litigant may not impose a choice of language on other participants.
Official Documents Translated
An individual may be entitled to have the State translate documents, where a failure to do so would impede that his right to conduct his case through Irish.
The recognition of Irish as the first official language and held to oblige the State provide dual language version of certain official forms which it is necessary for citizens to undertake their lawful business. The case has been limited in other cases.
Requirement for Language in Employment
In a case before the ECJ, the requirement of ability in Irish as a necessary qualification for public sector employment was claimed to impede a Dutch national’s right to establish in the State under EU freedom of movement provisions.
The relevant Council regulation provides that provisions does not apply to conditions relating to linguistic knowledge required by reason of nature the post to be fulfilled. The ECJ accepted the importance of policy for the protection and promotion of language which is the first official language.  Teachers could be required to have some knowledge of the language.
The implementation of the policy could not encroach upon the fundamental freedom of movement. Specific requirements derived from the policy would only be acceptable where they were not disproportionate in relation to the aim and the manner of their application did not discriminate against nationals of other State. In that case, a fulltime post of lecturer in a public education institution was such that the linguistic requirement was proportionate and non-discriminatory.