Irish declension
The declension of Irish nouns, the definite article, and the adjectives is discussed on this page (for pronouns, see Irish morphology). 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. 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 is used in the following functions: Vocative. The vocative 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. Genitive. The genitive indicates possession and material of composition: The object of a verbal noun also requires the genitive: The object of a compound preposition is in the genitive. Formally, these prepositions are actually prepositional phrases. 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 the head" – "cionn" is the old dative of "ceann" ("head")). Declension. There are five recognized declensions in Irish. The makeup of the declensions depends on three factors: The following chart describes the characteristics of each declension class: 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 "-aibh" is still sometimes encountered in old-fashioned literary style. When in the gen. sing. and nom. pl. of a polysyllabic word is made slender, it also becomes voiced, thus: Some nouns undergo a vowel change before  the slender consonant of the genitive singular/nominative plural: 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: 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": Other strong plural formations are found in: 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. 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. Many words in this declension form a strong plural with one of the endings "-t(h)a,-te, -(e)acha" or "-eanna": Other strong plural formations are found in: 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. Feminine nouns in "-áint and -úint" lose their "t" in the gen. sg.; those in "-irt" have "-th-" instead of "-t-" in the gen. sg. Many words in this declension form the plural with one of the endings "-anna" or "-acha": Some words in Munster Irish also have a separate dative form: 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". Many words of this declension form the plural with the following endings "-tha/-t(h)e", "-((e)a)nna" or "-((e)a)cha": Other strong plural formations are found in: One noun in this class has a weak plural: 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. 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". In "Ireland" the dative is still used 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". Other strong plural formations are found in: Some nouns have weak plurals; here the genitive singular and genitive plural have the same form: 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. The 1st conjugation verbal noun in "-(e)adh" has a genitive singular in "-te/-ta" and a plural in "-t(a)í". The 2nd conjugation verbal noun in "-(i)ú" has a genitive singular in "-(a)ithe" and a plural in "-(u)ithe". These endings  are pronounced the same regardless of the spelling distinction. Irregular nouns. The following nouns are declined irregularly: Articles. 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. Each entry of the table gives an example of one noun starting with a consonant and one with a vowel. Dative (i) is used with all prepositions in Ulster usage; in Munster and the standard language it is used only with "from the", "to the", and "in the" but  there are also Munster dialects in which only "sa(n)" triggers lenition and "den" and "don" eclipse, as with every other article-preposition compound. In Connacht "sa(n)" eclipses whereas "den" and "don" lenite. Dative (ii) is used outside Ulster with other prepositions. The article never mutates a following or in the singular, and is lenited to (pronounced ) rather than the usual . "s" furthermore lenites in both dative (i) and (ii) in the singular with feminine nouns but does not lenite at all with masculine nouns. It does, however, eclipse "t" and "d" in Munster dialects and forms like "ag an ndoras  instead of the usual pattern ag an doras", which is used in all other dialects, do occur. There is no indefinite article in Irish, so depending on context can mean "cat" or "a cat". Adjectives. Almost all adjectives in Irish can be used either predicatively or attributively. A predicative adjective is one that forms a part of the predicate, like "red" in the sentence "The car is red." An attributive adjective directly modifies a noun, as in "the red car". A predicate adjective in Irish does not inflect: A predicate adjective expressing a value judgment is often preceded by the  particle . This particle attaches a "h" to a following vowel. In Ulster, "go" is not generally used in these cases. An attributive adjective mostly follows the noun and is inflected: There are four classes of declension of adjectives in Irish, which correspond to the first four declensions of nouns: Fourth declension. This declension does not inflect, but it does mutate. Comparative. Irish adjectives have a comparative form equivalent to the comparative and superlative in English. The comparative does not undergo inflexion and is the same as the feminine singular genitive in regular and many irregular adjectives. Syntax of comparison. There  are two constructions to express the comparative: 1) Copula + comparative form + subject + ("than") + predicate. The preterite of the copula causes lenition, while the present tense does not. 2) + comparative + + predicate. is used if the sentence is in the present or future tense. , which triggers lenition, is used if the sentence is in the past tense. is used before words starting with vowels and before those starting with consonants. A superlative is expressed as a relative clause: noun + + comparative form.