In Irish grammar, declension happens to nouns, the definite article, and the adjectives.
Irish mostly has five noun declensions, each with four cases (nominative, vocative, genitive, dative), and singular and plural forms. There are four classes of declension of adjectives in Irish, which correspond to the first four declensions of nouns. There are two genders in Irish, masculine and feminine. The gender of nouns in each declension is somewhat mixed, but there are clear patterns.
The definite article has two forms in Irish: and . Their distribution depends on number, case, and gender, and they trigger mutation partly on the basis of the initial sound of the following word. There is no indefinite article in Irish, so depending on context can mean "cat" or "a cat".
Nouns
Gender Nouns in Irish are divided into two genders, masculine and feminine; the Old Irish neuter gender no longer exists. While gender should be learned when the specific noun is learned, there are some guidelines that can be followed:
Generally, nouns in singular form ending with broad consonants are masculine, while those ending in a slender consonant are feminine. (Help:IPA/Irish shows the difference)
There are some exceptions, mostly dealing with specific endings and suffixes; for example, words ending in / and (with a slender and respectively) are categorically masculine, while words ending in (with a broad ) are feminine. This leads to some unexpected gender assignments, such as "boy scout" being feminine, and "girl" masculine (the diminutive suffix is always masculine irrespective of the noun it applies to).
Case Irish has four cases: common (usually called the nominative, but it covers the role of the accusative as well), vocative, genitive, and the dative or prepositional case.
Nominative The nominative case () is used in the following functions: Sentence subject "The cat is drinking." Sentence object "Seán broke the window." Predicate of the copula "He is an idiot." Object of the prepositions "without", "(up) to" and "like, as". "without the money" "(up) to the time" "like the hen"
Vocative The vocative case () is used in direct address, and is always preceded by the particle , which triggers 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. → "Where are you, son?" → "Seán, come here!"
Genitive The genitive case () indicates possession and material of composition: → ("the man's hat") → ("the woman's children") → ("the bishop's candelabras") → ("a ring of gold, a golden ring") → ("shoes of leather, leather shoes")
The object of a verbal noun also requires the genitive: → "(the act of) spending money"
The object of a compound preposition is in the genitive. Formally, these prepositions are actually prepositional phrases. → "behind the door" (lit. "on the back of the door") → "one month long" (lit. "for the duration of one month") → "for Ireland's sake"
Dative/Prepositional The dative/prepositional is used as the object of most simple prepositions except and . 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 ("Ireland") and ("twenty") have distinct datives - and , respectively. They are also found in certain fixed phrases with nouns of the second declension, such as ("above", lit. "over head" – is the old dative of ("head")). → "at the father" → "out of the house" → "on the bread" → "in an orange" → "to hell" → "with the money" → "from Ireland"
Declension There are five recognized declensions in Irish. The makeup of the declensions depends on three factors: the gender of the noun the formation of the genitive singular relation of genitive singular to nominative plural
The following chart describes the characteristics of each declension class: Nom. sing. ends with: Gen. sing. ends with: Gender First declension Broad consonant Slender consonant Masculine Second declension Broad or slender consonant -e/-í Feminine with rare exceptions Third declension Slender or broad consonant -a Masculine or feminine Fourth declension Vowel or -ín (no change) Masculine or feminine Fifth declension Vowel or slender consonant Broad consonant Mostly feminine
First The first declension is made up of masculine nouns. The nominative singular ends in a broad consonant, which is made slender in the genitive singular. The most common formation of the plural has the opposite pattern: the nominative ends in a slender consonant, the genitive in a broad consonant (these plurals are known as weak plurals in comparison with strong plurals which maintain identical endings for all cases in the plural). The dative is identical to the nominative in both numbers, although an obsolete dative plural in is still sometimes encountered in old-fashioned literary style.
"boat" Singular Plural Nominative Vocative Genitive Dative (obsolete )
When in the gen. sing. and nom. pl. of a polysyllabic word is made slender, it also becomes voiced, thus: > > . The resulting is written - and is pronounced , , or , depending on dialect. "a horseman" Singular Plural Nominative Vocative Genitive Dative (obsolete )
Some nouns undergo a vowel change before the slender consonant of the genitive singular/nominative plural: - an (internal) organ, component part - a sole, coin - a head - a man - a fish - a son (note: the first consonant is made slender in the gen.sg./nom.pl. as well) - a hole
Many words of this declension form the plural with one of the endings -(a)í, -ta, -tha, -anna. These are known as "strong plural" endings, which means the plural is identical in all cases in the standard language. Some examples: , gen. sg. , pl. - a fair , gen. sg. , pl. - a way , gen. sg. , pl. - a car , gen. sg. , pl. - a voice , gen. sg. , pl. - a child , gen. sg. , pl. - a cloud , gen. sg. , pl. - a rose , gen. sg. , pl. - a summer , gen. sg. , pl. - a story , gen. sg. , pl. - fruit
Some nouns have a weak plural (a plural where the genitive is different from the nominative, and is identical to the form of the nominative singular) in -a: , gen. sg. , nom. pl. , gen. pl. - a right , gen. sg. , nom. pl. , gen. pl. - a trick , gen. sg. , nom. pl. , gen. pl. - an apple
Other strong plural formations are found in: - road - judge - verb - skull - door - professor - light
Second The second declension is made up of mostly feminine nouns, and features a nominative singular form that can end in either a broad or a slender consonant. The genitive singular ends in a slender consonant followed by -e. The most common plural form has a broad consonant followed by -a in the nominative, and a broad consonant alone in the genitive. The vocative has the same endings as the nominative, as does the dative in standard language. "shoe" Singular Plural Nominative Vocative Genitive Dative (obsolete/dialectal ) (obsolete ) "tear" Singular Plural Nominative/Dative Vocative Genitive In Connacht Irish and Waterford Irish it is often the case that all nouns of the second declension in the nom. sg. end with a slender consonant (e.g. "a shoe").
In some Munster varieties as well as the old literary language, the dative singular is distinct and ends in a slender consonant alone (in effect the dative sg. is formed by dropping the -e from the genitive sg.), e.g. "in my shoe" (historically, nominative forms like are descended from the old dative).
When in the gen. sing. is made slender, it is also voiced, so > > . becomes , and is written -(a)í. "little girl" Singular Plural Nominative/Std. dative Vocative Genitive Nonstandard Dative (obsolete/dialectal) (obsolete)
Many words in this declension form a strong plural with one of the endings -t(h)a,-te, -(e)acha or -eanna: "place" "forest" "daughter" "work" "sky" "country" "wave" "egg"
Other strong plural formations are found in: - tooth - shoulder - knife (irregular genitive singular) (m.) - mountain (irregular genitive singular and masculine gender)
Third The third declension is made up of masculine and feminine nouns. It is characterized by the genitive singular in -a. The majority of nouns in this class form the plural in -(a)í. The final consonant of the stem may be broad or slender: it retains its quality in the plural, but is always broad in the genitive singular. Singular Plural Nominative/Vocative/Dative broad or slender cons. -(a)í Genitive broad cons. + -a -(a)í (m.) "boatsman" Singular Plural Nominative/Dative Vocative Genitive (m.) "race" Singular Plural Nominative/Dative Vocative Genitive Feminine nouns in -áint or -úint lose their in the gen. sg.; those in -irt have -- instead of -- in the gen. sg. (f.) "threat" (f.) "dialect"
Many words in this declension form the plural with one of the endings -anna or -acha: (m.) "time" (m.) "soul" (m.) "back" (m.) "lake" (f.) "fight, struggle"
Some words in Munster Irish also have a separate dative form: nom. , dat. , gen. , pl. (m.) "back"
Fourth The fourth declension is made up of masculine and feminine nouns. It is characterized by a genitive singular that is identical in form to the nominative/vocative/dative singular. The singular may end in a vowel or a consonant (usually the diminutive suffix -ín). The most common plural ending is -(a)í. Singular Plural All cases Vowel or consonant (usually -ín) -(a)í (m.) "wall" Singular Plural Nominative/Genitive/Dative Vocative (f.) "(piece of) advice" Singular Plural Nominative/Genitive/Dative Vocative (m.) "girl" Singular Plural Nominative/Genitive/Dative Vocative
Many words of this declension form the plural with the following endings -tha/-t(h)e, -((e)a)nna or -((e)a)cha: (m.) "animal" (m.) "attorney" (m.) "village" (m.) "bus" (m.) "son-in-law" (f.) "wound, sore" (m.) "nut" (m.) "outhouse; eye of a needle" (m.) "law" (m.) "dozen" (m.) "ray, radius" (f.) "goose" (f.) "shirt" (m.) "saying" (m.) "king" (m.) "last name" (f.) "language, tongue" (f.) "fire"
Other strong plural formations are found in: (m.) "name" (m.) "characteristic, symptom" (f.) "commandment" (m.) "bank (of river etc.)" (m.) "race, tribe" (m.) "person, human being" (m.) "blacksmith" (m.) "business" (f.) "night"
One noun in this class has a weak plural: (f.) - cow
Fifth The fifth declension is made up mostly of feminine nouns and is characterized by a genitive singular that ends in a broad consonant that has been added to the nominative/vocative/dative singular. The most common plural is strong, formed by adding -a to the genitive singular. Singular Plural Nominative/Vocative/Dative Vowel or slender consonant Gen. sg. + -a Genitive broad consonant Gen. sg. + -a "person" Singular Plural Nominative/Dative Vocative Genitive "city" Singular Plural Nominative/Dative Vocative Genitive In some Munster Irish varieties as well as the old literary language, the dative singular is distinct and ends in a slender consonant (in effect the dative sg. is formed by palatalizing the genitive sg.), for example, "to a person", "from the city". The word ("Ireland") retains the distinct dative form in the standard language.
Some words form the genitive singular by changing the final consonant of the nominative singular to broad. The plural is then strong -eacha. "river" (m.) "father" (m.) "brother" "mother"
Other strong plural formations are found in: (m.) "brother (monk), friar" (m.) "friend" (m.) "enemy" "Christmas"
Some nouns have weak plurals; here the genitive singular and genitive plural have the same form: - sheep - duck
Verbal nouns The most productive verbal nouns end with -(e)adh (1st conjugation) or -(i)ú (2nd conjugation). These originally belonged to the third declension, but synchronically are best regarded as separate declensions.