Editing Irish declension (section)

===Case===
Irish has four [[grammatical case|case]]s: common (usually called the [[nominative]], but it covers the role of the [[accusative]] as well), [[vocative]], [[genitive]], and the [[prepositional case|dative or prepositional]] case.

====Nominative====
The nominative case ({{lang|ga|an tuiseal ainmneach}}) is used in the following functions:
# Sentence subject
#:{{lang|ga|Tá an '''cat''' ag ól.}} "The cat is drinking."
# Sentence object
#:{{lang|ga|Bhris Seán an '''fhuinneog'''.}} "Seán broke the window."
# Predicate of the [[Irish syntax#The copula is|copula]]
#:{{lang|ga|Is '''amadán''' é.}} "He is an idiot."
# Object of the [[preposition]]s {{lang|ga|gan}} "without", {{lang|ga|go dtí}}  "(up) to" and {{lang|ga|mar}} "like, as".
#:{{lang|ga|gan an '''t-airgead'''}} "without the money"
#:{{lang|ga|go dtí an '''t-am'''}} "(up) to the time"
#:{{lang|ga|mar an '''chearc'''}} "like the hen"

====Vocative====
The vocative case ({{lang|ga|an tuiseal gairmeach}}) is used in direct address, and is always preceded by the [[grammatical particle|particle]] {{lang|ga|a}}, which triggers [[Irish initial mutations|lenition]] (the vocative  particle is not pronounced before a [[vowel]] sound).  The first declension is the only declension in which the vocative is distinct from the nominative.
*[[wikt:mac#Irish|mac]] → {{lang|ga|Cá bhfuil tú, '''a mhic'''?}} "Where are you, son?"
*[[wikt:Seán#Irish|Seán]] → {{lang|ga|'''A Sheáin''', tar anseo!}} "Seán, come here!"

====Genitive====
The genitive case ({{lang|ga|an tuiseal ginideach}}) indicates possession and material of composition:
*[[wikt:fear#Irish|fear]] → {{lang|ga|hata an '''fhir'''}} ("the man's hat")
*[[wikt:bean#Irish|bean]] → {{lang|ga|clann na '''mná'''}} ("the woman's children")
*[[wikt:easpag#Irish|easpag]] → {{lang|ga|coinnleoirí an '''easpaig'''}} ("the bishop's candelabras")
*[[wikt:ór#Irish|ór]] → {{lang|ga|fáinne '''óir'''}} ("a ring of gold, a golden ring")
*[[wikt:leathar#Irish|leathar]] → {{lang|ga|bróga '''leathair'''}} ("shoes of leather, leather shoes")

The object of a [[verbal noun]] also requires the genitive:
*[[wikt:airgead#Irish|airgead]] → {{lang|ga|ag caitheamh '''airgid'''}} "(the act of) spending money"

The object of a [[Compound (linguistics)|compound]] preposition is in the genitive. Formally, these prepositions are actually prepositional phrases.
*[[wikt:doras#Irish|doras]] → {{lang|ga|ar chúl an '''dorais'''}} "behind the door" (lit. "on the back of the door")
*[[wikt:mí#Irish|mí]] → {{lang|ga|ar feadh '''míosa'''}} "one month long" (lit. "for the duration of one month")
*[[wikt:Éire#Irish|Éire]] → {{lang|ga|ar son na '''hÉireann'''}} "for Ireland's sake"

====Dative/Prepositional====
The dative/prepositional is used as the object of most simple prepositions except {{lang|ga|gan}} and {{lang|ga|go dtí}}. In [[standard language]], the dative is almost always identical to the nominative. Some dialects, however, have distinct standalone datives in the second and fifth declensions.  In the standard language, only two words {{lang|ga|Éire}} ("Ireland") and {{lang|ga|fiche}} ("twenty") have distinct datives - {{lang|ga|Éirinn}} and {{lang|ga|fichid}}, respectively. They are also found in certain fixed phrases with nouns of the second declension, such as {{lang|ga|os cionn}} ("above", lit. "over head" – {{lang|ga|cionn}} is the old dative of {{lang|ga|ceann}} ("head")).
*[[wikt:athair#Irish|athair]] → {{lang|ga|ag an '''athair'''}} "at the father"
*[[wikt:teach#Irish|teach]] → {{lang|ga|as an '''teach'''}} "out of the house"
*[[wikt:arán#Irish|arán]] → {{lang|ga|ar an '''arán'''}} "on the bread"
*[[wikt:oráiste#Irish|oráiste]] → {{lang|ga|in '''oráiste'''}} "in an orange"
*[[wikt:ifreann#Irish|ifreann]] → {{lang|ga|go '''hifreann'''}} "to hell"
*[[wikt:airgead#Irish|airgead]] → {{lang|ga|leis an '''airgead'''}} "with the money"
*[[wikt:Éire#Irish|Éire]] → {{lang|ga|ó '''Éirinn'''}} "from Ireland"