The declension of Irish nouns, the definite article, and the adjectives is discussed on this page (for pronouns, see Irish Grammar).
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 Irish: -óir/-eoir and Irish: -ín (with a slender pronounced as //ɾʲ// and pronounced as //nʲ// respectively) are categorically masculine, while words ending in Irish: -óg/-eog (with a broad pronounced as //ɡ//) are feminine. This leads to some unexpected gender assignments, such as Irish: gasóg "boy scout" being feminine, and Irish: cailín "girl" masculine (the diminutive Irish: -ín suffix is always masculine irrespective of the noun it applies to).
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.
The nominative is used in the following functions:
Irish: Tá an '''cat''' ag ól. "The cat is drinking."
Irish: Bhris Seán an '''fhuinneog'''. "Seán broke the window."
Irish: Is '''amadán''' é. "He is an idiot."
Irish: gan an '''t-airgead''' "without the money"
Irish: go dtí an '''t-am''' "(up) to the time"
Irish: mar an '''chearc''' "like the hen"
The vocative is used in direct address, and is always preceded by the particle Irish: a, 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.
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.
The dative/prepositional is used as the object of most simple prepositions except Irish: gan and Irish: 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 Irish: Éire ("Ireland") and Irish: fiche ("twenty") have distinct datives - Irish: Éirinn and Irish: fichid, respectively. They are also found in certain fixed phrases with nouns of the second declension, such as Irish: os cionn ("above", lit. "over head" – Irish: cionn is the old dative of Irish: ceann ("head")).
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:
| 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 |
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 Irish: -aibh is still sometimes encountered in old-fashioned literary style.
| width=150px | Irish: bád "boat" | width=200px | Singular | width=200px | Plural |
|---|---|---|---|---|---|
| Nominative | Irish: bád pronounced as //bˠaːd̪ˠ// | Irish: báid pronounced as //bˠaːdʲ// | |||
| Vocative | Irish: a bháid pronounced as //ə waːdʲ// | Irish: a bháda pronounced as //ə waːd̪ˠə// | |||
| Genitive | Irish: báid pronounced as //bˠaːdʲ// | Irish: bád pronounced as //bˠaːd̪ˠ// | |||
| Dative | Irish: bád pronounced as //bˠaːd̪ˠ// | Irish: báid (obsolete Irish: bádaibh) |
When pronounced as //x// in the gen. sing. and nom. pl. of a polysyllabic word is made slender, it also becomes voiced, thus:
| width=150px | Irish: marcach "a horseman" | width=200px | Singular | width=200px | Plural |
|---|---|---|---|---|---|
| Nominative | Irish: marcach pronounced as //mˠaɾˠkəx// | Irish: marcaigh pronounced as //mˠaɾˠkəj// | |||
| Vocative | Irish: a mharcaighpronounced as //ə waɾˠkəj// | Irish: a mharcacha pronounced as //ə waɾˠkəxə// | |||
| Genitive | Irish: marcaighpronounced as //mˠaɾˠkəj// | Irish: marcach pronounced as //mˠaɾˠkəx// | |||
| Dative | Irish: marcachpronounced as //mˠaɾˠkəx// | Irish: marcaigh (obsolete Irish: marcachaibh) |
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:
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.
| Irish: bróg "shoe" | Singular | Plural | |
|---|---|---|---|
| Nominative | Irish: bróg pronounced as //bˠɾˠoːɡ// | Irish: bróga pronounced as //ˈbˠɾˠoːɡə// | |
| Vocative | Irish: a bhróg pronounced as //ə wɾˠoːɡ// | Irish: a bhróga pronounced as //ə ˈwɾˠoːɡə// | |
| Genitive | Irish: bróige pronounced as //ˈbˠɾˠoːɟə// | Irish: bróg pronounced as //bˠɾˠoːɡ// | |
| Dative | Irish: bróg pronounced as //bˠɾˠoːɡ// (obsolete/dialectal Irish: bróig) | Irish: bróga pronounced as //ˈbˠɾˠoːɡə// (obsolete Irish: brógaibh) |
| Irish: deoir "tear" | Singular | Plural | |
|---|---|---|---|
| Nominative/Dative | Irish: deoir pronounced as //dʲoːɾʲ// | Irish: deora pronounced as //ˈdʲoːɾˠə// | |
| Vocative | Irish: a dheoir pronounced as //ə joːɾʲ// | Irish: a dheora pronounced as //ə ˈjoːɾˠə// | |
| Genitive | Irish: deoire pronounced as //ˈdʲoːɾʲə// | Irish: deor pronounced as //dʲoːɾˠ// |
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. Irish: i mo bhróig "in my shoe" (historically, nominative forms like Irish: bróig are descended from the old dative).
When pronounced as //x// in the gen. sing. is made slender, it is also voiced, so pronounced as //x// > pronounced as //ç// > pronounced as //j//. pronounced as //əjə// becomes pronounced as //iː//, and is written -(a)í.
| Irish: girseach "little girl" | Singular | Plural | |
|---|---|---|---|
| Nominative/Std. dative | Irish: girseach pronounced as //ˈɟɪɾˠʃəx// | Irish: girseacha pronounced as //ˈɟɪɾˠʃəxə// | |
| Vocative | Irish: a ghirseach pronounced as //ə ˈjɪɾˠʃəx// | Irish: a ghirseacha pronounced as //ə ˈjɪɾˠʃəxə// | |
| Genitive | Irish: girsí pronounced as //ˈɟɪɾˠʃiː// | Irish: girseach pronounced as //ˈɟɪɾˠʃəx// | |
| Nonstandard Dative | Irish: girsigh pronounced as //ˈɟɪɾˠʃiː// (obsolete/dialectal) | Irish: girseachaibh pronounced as //ˈɟɪɾˠʃəxəvʲ// (obsolete) |
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:
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 |
| Irish: bádóir (m.) "boatsman" | Singular | Plural | |
|---|---|---|---|
| Nominative/Dative | Irish: bádóir pronounced as //ˈbˠaːd̪ˠoːɾʲ// | Irish: bádóirí pronounced as //ˈbˠaːd̪ˠoːɾʲiː// | |
| Vocative | Irish: a bhádóir pronounced as //ə ˈwaːd̪ˠoːɾʲ// | Irish: a bhádóirí pronounced as //ə ˈwaːd̪ˠoːɾʲiː// | |
| Genitive | Irish: bádóra pronounced as //ˈbˠaːd̪ˠoːɾˠə// | Irish: bádóirí pronounced as //ˈbˠaːd̪ˠoːɾʲiː// |
| Irish: rás (m.) "race" | Singular | Plural | |
|---|---|---|---|
| Nominative/Dative | Irish: rás pronounced as //ɾˠaːsˠ// | Irish: rásaí pronounced as //ˈɾˠaːsˠiː// | |
| Vocative | Irish: a rás pronounced as //ə ɾˠaːsˠ// | Irish: a rásaí pronounced as //ə ˈɾˠaːsˠiː// | |
| Genitive | Irish: rása pronounced as //ˈɾˠaːsˠə// | Irish: rásaí pronounced as //ˈɾˠaːsˠiː// |
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:
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 |
| Irish: balla (m.) "wall" | Singular | Plural | |
|---|---|---|---|
| Nominative/Genitive/Dative | Irish: balla pronounced as //ˈbˠal̪ˠə// | Irish: ballaí pronounced as //ˈbˠal̪ˠiː// | |
| Vocative | Irish: a bhalla pronounced as //ə ˈwal̪ˠə// | Irish: a bhallaí pronounced as //ə ˈwal̪ˠiː// |
| Irish: comhairle (f.) "(piece of) advice" | Singular | Plural | |
|---|---|---|---|
| Nominative/Genitive/Dative | Irish: comhairle pronounced as //ˈkoːɾˠl̠ʲə// | Irish: comhairlí pronounced as //ˈkoːɾˠl̠ʲiː// | |
| Vocative | Irish: a chomhairle pronounced as //ə ˈxoːɾˠl̠ʲə// | Irish: a chomhairlí pronounced as //ə ˈxoːɾˠl̠ʲiː// |
| Irish: cailín (m.) "girl" | Singular | Plural | |
|---|---|---|---|
| Nominative/Genitive/Dative | Irish: cailín pronounced as //ˈkalʲiːnʲ// | Irish: cailíní pronounced as //ˈkalʲiːnʲiː// | |
| Vocative | Irish: a chailín pronounced as //ə ˈxalʲiːnʲ// | Irish: a chailíní pronounced as //ə ˈxalʲiːnʲiː// |
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:
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 |
| Irish: pearsa "person" | Singular | Plural | |
|---|---|---|---|
| Nominative/Dative | Irish: pearsa pronounced as //ˈpʲaɾˠsˠə// | Irish: pearsana pronounced as //ˈpʲaɾˠsˠən̪ˠə// | |
| Vocative | Irish: a phearsa pronounced as //ə ˈfʲaɾˠsˠə// | Irish: a phearsana pronounced as //ə ˈfʲaɾˠsˠən̪ˠə// | |
| Genitive | Irish: pearsan pronounced as //ˈpʲaɾˠsˠən̪ˠ// | Irish: pearsana pronounced as //ˈpʲaɾˠsˠən̪ˠə// |
| Irish: cathair "city" | Singular | Plural | |
|---|---|---|---|
| Nominative/Dative | Irish: cathair pronounced as //ˈkahəɾʲ// | Irish: cathracha pronounced as //ˈkaɾˠəxə// | |
| Vocative | Irish: a chathair pronounced as //ə ˈxahəɾʲ// | Irish: a chathracha pronounced as //ə ˈxaɾˠəxə// | |
| Genitive | Irish: cathrach pronounced as //ˈkaɾˠəx// | Irish: cathracha pronounced as //ˈkaɾˠəxə// |
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:
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 Irish: -(i)ú has a genitive singular in Irish: -(a)ithe and a plural in Irish: -(u)ithe. These endings are pronounced the same regardless of the spelling distinction.
The following nouns are declined irregularly:
The definite article has two forms in Irish: Irish: an and Irish: na. 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.
| Singular | Plural | |||
| Masculine | Feminine | both genders | ||
| Nominative | Irish: '''an c'''at Irish: '''an t-'''éan | Irish: '''an bh'''róg Irish: '''an''' eaglais | Irish: (do) '''na c'''ait Irish: (leis) '''na h'''éin | |
| Dative (i) | Irish: '''den ch'''at Irish: '''san''' éan | Irish: '''don bh'''róg Irish: '''den''' eaglais | ||
| Dative (ii) | Irish: ag '''an gc'''at Irish: ag '''an''' éan | Irish: faoi'''n mb'''róg Irish: tríd '''an''' eaglais | ||
| Genitive | Irish: '''an ch'''ait Irish: '''an''' éin | Irish: '''na b'''róige Irish: '''na h'''eaglaise | na gcatna n-éan | |
The article never mutates a following or in the singular, and is lenited to (pronounced in Irish pronounced as /t̪ˠ, tʲ/) rather than the usual . 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 and in Munster dialects and forms like "Irish: ag '''an nd'''oras" instead of the usual pattern "Irish: ag '''an d'''oras", which is used in all other dialects, do occur.
There is no indefinite article in Irish, so depending on context Irish: cat can mean "cat" or "a cat".
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 Irish: go. This particle attaches to a following vowel.
In Ulster, Irish: 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:
| Nom. sg. ends with: | Gen. sg. masc. ends with: | Gen. sg. fem. ends with: | ||
| 1st decl. | broad cons. | slender consonant | slender consonant + -e | |
| 2nd decl. | slender cons. | slender consonant | slender consonant + -e | |
| 3rd decl. | slender cons. (mostly -úil) | slender consonant | broad consonant + -a | |
| 4th decl. | vowel | = nom. sg. | = nom. sg. |
| Irish: bocht "poor" | Masc. sg. | Fem. sg. | Plural | |
|---|---|---|---|---|
| Nominative | Irish: bocht | Irish: bhocht | Irish: b(h)ochta | |
| Genitive | Irish: bhoicht | Irish: boichte | Irish: bocht(a) |
| Irish: bacach "lame" | Masc. sg. | Fem. sg. | Plural | |
|---|---|---|---|---|
| Nominative | Irish: bacach | Irish: bhacach | Irish: b(h)acacha | |
| Genitive | Irish: bhacaigh | Irish: bacaí | Irish: bacach(a) |
| Irish: ciúin "quiet" | Masc. sg. | Fem. sg. | Plural | |
|---|---|---|---|---|
| Nominative | Irish: ciúin | Irish: chiúin | Irish: c(h)iúine | |
| Genitive | Irish: chiúin | Irish: ciúine | Irish: ciúin(e) |
| Irish: misniúil "brave" | Masc. sg. | Fem. sg. | Plural | |
|---|---|---|---|---|
| Nominative | Irish: misniúil | Irish: mhisniúil | Irish: m(h)isniúla | |
| Genitive | Irish: mhisniúil | Irish: misniúla | Irish: misniúil, -úla |
| Irish: cóir "just" | Masc. Sg. | Fem. Sg. | Plural | |
|---|---|---|---|---|
| Nominative | Irish: cóir | Irish: chóir | Irish: c(h)óra | |
| Genitive | Irish: chóir | Irish: córa | Irish: cóir, córa |
This declension does not inflect, but it does mutate.
| Irish: crua "hard" | Masc. sg. | Fem. sg. | Plural | |
|---|---|---|---|---|
| Nominative | Irish: crua | Irish: chrua | Irish: c(h)rua | |
| Genitive | Irish: chrua | Irish: crua | Irish: crua |
| Masc. sg. nom. & gen. | Fem. sg. nom. | Fem. sg. gen. | Pl. nom./gen. | Gloss | |
|---|---|---|---|---|---|
| Irish: álainn | Irish: álainn | Irish: áille | Irish: áille | "beautiful" | |
| Irish: breá | Irish: bhreá | Irish: breátha | Irish: b(h)reátha | "fine" | |
| Irish: deacair | Irish: dheacair | Irish: deacra | Irish: d(h)eacra | "difficult" | |
| Irish: gearr | Irish: ghearr | Irish: giorra | Irish: g(h)earra | "short" | |
| Irish: socair | Irish: shocair | Irish: socra | Irish: s(h)ocra | "still" | |
| Irish: tapaidh | Irish: thapaidh | Irish: thapaí | Irish: t(h)apaí | "fast" | |
| Irish: te | Irish: the | Irish: te | Irish: t(h)eo | "hot" | |
| Irish: tirim | Irish: thirim | Irish: tirime | Irish: t(h)iorma | "dry" |
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.
| Base form | Comparative form | Gloss | |
|---|---|---|---|
| Irish: álainn | Irish: áille | "beautiful/more beautiful" | |
| Irish: bacach | Irish: bacaí | "lame/lamer" | |
| Irish: bocht | Irish: boichte | "poor/poorer" | |
| Irish: ciúin | Irish: ciúine | "quiet/quieter" | |
| Irish: cóir | Irish: córa | "just/more just" | |
| Irish: crua | Irish: crua | "hard/harder" | |
| Irish: deacair | Irish: deacra | "difficult/more difficult" | |
| Irish: gearr | Irish: giorra | "short/shorter" | |
| Irish: misniúil | Irish: misniúla | "brave/braver" | |
| Irish: socair | Irish: socra | "still/stiller" | |
| Irish: tapaidh | Irish: tapaí | "fast/faster" | |
| Irish: tirim | Irish: tirime | "dry/drier" |
| Base form | Comparative form | Gloss | |
|---|---|---|---|
| Irish: beag | Irish: lú | "small/smaller" | |
| Irish: breá | Irish: breátha | "fine/finer" | |
| Irish: dócha | Irish: dóichí | "possible/more possible" | |
| Irish: fada | Irish: faide | "long/longer" | |
| Irish: fogus | Irish: foisce | "near/nearer" | |
| Irish: furasta | Irish: fusa | "easy/easier" | |
| Irish: iomaí | Irish: lia | "many/more" | |
| Irish: ionúin | Irish: ansa | "beloved, dear/more beloved, dearer" | |
| Irish: maith | Irish: fearr | "good/better" | |
| Irish: olc | Irish: measa | "bad/worse" | |
| Irish: te | Irish: teo | "hot/hotter" | |
| Irish: tréan | Irish: tréine or Irish: treise | "strong/stronger" | |
| Irish: mór | Irish: mó | "big/bigger" |
There are two constructions to express the comparative:
1) Copula + comparative form + subject + Irish: ná ("than") + predicate. The preterite of the copula causes lenition, while the present tense does not.
2) Irish: níos/ní ba/ní b’ + comparative + Irish: ná + predicate. Irish: Níos is used if the sentence is in the present or future tense.
Irish: Ní ba/ní b’, which triggers lenition, is used if the sentence is in the past tense. Irish: Ní b’ is used before words starting with vowels and Irish: ní ba before those starting with consonants.
A superlative is expressed as a relative clause: noun + Irish: is/ba/ab + comparative form.