Chapter 2 | The Noun

2.1 General

2.1.1 The Declensions

The nouns can be divided into five declensions, according to genitive case form, as is seen in table 2E.

2.1.2 The Cases

  1. The Nominative and the Accusative

    Both of these cases have the same form now, in the singular and in the plural, and they are both counted under the title Nominative in the declensions of nouns.

  2. The Dative

    The form of the dative is also the same as the nominative, singular and plural (but see 2.3.3), and that case is also counted under the title Nominative.

  3. The Genitive

    The form of the genitive in the different declensions is given in the tables in this chapter and in the description of the particular declensions.

  4. The Vocative

    In the vocative case, the vocative particle a is put before the noun and the initial consonant of the following noun is lenited. The form of the vocative is the same as the nominative except in the first declension and does not need to be specified separately outside of that declension (see 2.2.3 and 2.2.4(c)).

2.1.3 The Plural

The plurals of nouns can be divided into two main classes: strong plurals and weak plurals. The two classes are described as follows:

  1. Strong Plurals

    The plural of a noun is a strong plural if the noun’s plural form is the same in all the cases.

    Table 2A Examples of Strong Plurals
    The Declensions Singular Plural
    Nominative Genitive Nominative Genitive
    The First Declension cás cáis cásanna cásanna
    ceol ceoil ceolta ceolta
    The Second Declension foirm foirme foirmeacha foirmeacha
    sliabh sléibhe sléibhte sléibhte
    The Third Declension feirmeoir feirmeora feirmeoirí feirmeoirí
    foráil forála forálacha forálacha
    The Fourth Declension amhránaí amhránaí amhránaithe amhránaithe
    gloine gloine gloiní gloiní
    The Fifth Declension deartháir dearthár deartháireacha deartháireacha
    lasair lasrach lasracha lasracha
    Irregular Nouns leaba leapa leapacha leapacha
    teach tí tithe tithe

  2. Weak Plurals

    The plural of a noun is a weak plural if the noun’s plural form is not the same in the genitive plural as the noun’s plural form in the other cases. This class includes:

    1. Nouns that end on a broad consonant and the ending consonant becomes slender in the nominative plural and the genitive singular, e.g., fear, tá na fir ag teacht, hata an fhir; eitleán, feictear na heitleáin sa spéir, athraíodh roth an eitleáin. Those nouns are only in the First Declension. An example is in the table below:

      Table 2B The First Declension — Weak Plural
      The First Declension
      Nominative Genitive
      Singular fear fir
      Plural fir fear

    2. Nouns that take an a in the nominative plural with neither syncope nor an exchange of vowel or vowels nor broadening in the nominative singular — lose the ending vowel -a in the genitive plural. Those plurals are mostly in the Second Declension, e.g., géag crainn, do ghéaga a shíneadh, laige na ngéag. This is shown in the table below:

      Table 2C The Second Declension — Weak Plural
      The Second Declension
      Nominative Genitive
      Singular fuinneog fuinneoige
      Plural fuinneoga fuinneog

      Note that several nouns follow the same pattern as in the First Declension, e.g., úll, itheadh na húlla, blas na n‑úll; in the Third Declension, e.g., tréad caorach, tréada is comhaltas, seoladh na dtréad; and in the Fourth Declension, e.g., gach aon neach, na neacha daonna, teacht na neach neamhshaolta.

    3. A few nouns in the Second Declension, e.g., súil, leath na súile uirthi, radharc na súl; a few in the Third Declension, e.g., mionn, na mionnaí marbha, dar bhrí na mionn; a few in the Fourth Declension, e.g., bó, tá na ba sa gharraí, cró na mbó; a few in the Fifth Declension, e.g., caora, tá na caoirigh ann, líon na gcaorach; and an occasional irregular noun, e.g., bean, tá na mná ag teacht, hataí na mban; have a separate form in the genitive plural. Examples are shown in the table below:

      Table 2D Other Weak Plurals — Examples
      The Declensions Singular Plural
      Nominative Genitive Nominative Genitive
      The Second Declension ealaín ealaíne ealaíona ealaíon
      súil súile súile súl
      The Third Declension mionn mionna mionnaí mionn
      The Fourth Declension bó bó ba bó
      grásta grásta grásta grást
      The Fifth Declension caora caorach caoirigh caorach
      lacha lachan lachain lachan
      Irregular Nouns bean mná mná ban
      olann olla olanna olann

2.1.4 Palatalization

When a broad consonant is made slender, this is palatalization. An -i- is placed before the end consonant to indicate a palatalization, e.g., cnoc, cnoic. The palatalization is done in the same way if the end-consonant has an ae in front, e.g., aer, aeir.

It is customary to change certain vowels when the following consonant is narrowed:

  1. -ea- and -io- to -i-, e.g., ceann, cinn; fionn, finn (but in certain monosyllabic nouns ea- to ei-, e.g., each, eich);

  2. -éa- and -ia- to éi-, e.g., béal, béil; iasc, éisc;

  3. -ío- to -í-, e.g., síol, síl;

  4. in the polysyllabic nouns, -ach to -aigh, -each to -igh, -ioch to -igh, e.g., bithiúnach, bithiúnaigh; cléireach, cléirigh; gaiscíoch, gaiscígh. That change applies to these monosyllabic nouns which were once written as disyllabic nouns, e.g., dúch, dúigh; fiach, fiaigh; and occasionally with other monosyllabic nouns, e.g., fraoch, fraoigh.

2.1.5 Broadening

When a slender consonant is made broad, this is broadening. The -i- directly in front of the consonant is dropped to broaden the noun, e.g., athair, athar; droim, droma.

It is customary to change certain vowels as follows when they are broadened:

  1. -ei- and -i- to -ea-, e.g., greim, greama; mil, meala;

  2. -éi- to -éa-, e.g., úinéir, úinéara;

  3. -oi- and -ui- to -o-, e.g., fuil, fola; toil, tola.

2.1.6 Syncopation

When a short, unaccented vowel or vowels are dropped from the word when it is inflected, this is syncopation, e.g., cathair, cathrach; obair, oibre.

2.1.7 The Compound Word

A compound word is made by connecting two words or more together, e.g, bunscoil; príomhoifigeach; ríomheolaíocht. The second word in a compound word is lenited, e.g., deargbhuile; rósghairdín, except when d, n, t, l or s come with it, e.g., antráth; catsúil. The hyphen is used in a compound:

  1. between two vowels, e.g., fo-aicme; mí-ádh; mí-iompar; ró-olc;

  2. between common consonants, e.g., droch-chaint; gearr-rás; gnáth-thuarastal;

  3. between two prefixes, e.g., comh-cheolfhoireann; mór-cheoldráma; sin-seanathair;

  4. in contexts when the compound would be unrecognizable without the hyphen, for example, between the prefixes do-, fo-, so- and words starting with bha-, bhla-, bhra-, dha-, gha-, ghla-, ghra-, mha-, e.g., do-ghlanta; fo-bhaile; so-mharaithe;

  5. in specific titles and their initial letters, e.g., an Ard-Chúirt; an tArd-Aighne; an Príomh-Aire; an Príomh-Bhreitheamh;

  6. after an- (emphatic prefix) and after dea-, e.g., an-aimsir; dea-bhéas. Note that the second word is not lenited in a compound word after an- when d, t or s follows it, e.g., an-duine is ea é; an-drochaimsir (see 10.2.12).

Note

  1. Two hyphens are placed in a compound word when it is necessary for the sake of clarity, e.g., an-dea-aimsir; an-droch-chaint; iar-nua-aimseartha; an Leas-Phríomh-Aire.

  2. The placement of a hyphen is not needed in an administrative term with more than one prefix if the meaning of the term is clear without it, e.g., comhfhochoiste; roghfhochoiste.

  3. Note if iar is coming before a title starting with a capital letter, the placement of a hyphen is not necessary between iar and the title, e.g., an t‑iarArd-Reachtaire Cuntas agus Ciste.

2.1.8 A Brief Overview of the Declensions

Table 2E A Brief Overview of the Declensions
The First Declension
Gender Nominative Singular Genitive Singular Nominative Plural Genitive Plural
Masculine Ends with a broad consonant, e.g., bád, cás, ceol, marcach. Palatalization of the last consonant, e.g., báid, cáis, ceoil, marcaigh. The form is usually the same as in the genitive singular, e.g., báid, marcaigh. The form is usually the same as in the nominative singular, e.g., bád, marcach.
The form in the plural is completely the same. e.g., cásanna, ceolta
The Second Declension
Gender Nominative Singular Genitive Singular Nominative Plural Genitive Plural
Feminine, but not im, sliabh. Ends with a consonant (broad or slender), e.g., aisling, áit, baintreach, bróg, coill, foirm, muinín, pian, scornach, tír. Ends with -e, e.g., aislinge, áite, bróige, coille, foirme, muiníne, péine, tíre; or with -(a)í, e.g., baintrí, scornaí. Ends with -a, e.g., baintreacha, bróga, scornacha. The -a is omitted, e.g., baintreach, bróg, scornach.
Ends with -a, -e, -(e)acha, -(e)anna, -í, -t(h)a, -te and is completely the same as the plural form, e.g., aislingí, áiteanna, coillte, foirmeacha, pianta, tíortha.
The Third Declension
Gender Nominative Singular Genitive Singular Nominative Plural Genitive Plural
Masculine and Feminine Ends with a consonant (broad or slender), e.g., bádóir, éacht, foráil, gleann, lus, táin. Ends with -a, e.g., bádóra, éachta, forála, gleanna, lusa, tána. Ends with -a, -acha, -(a)í, -(e)anna, -ta, -te and the form is completely the same as in the plural, e.g., bádóirí, éachtaí, forálacha, gleannta, lusanna, táinte.
The Fourth Declension
Gender Nominative Singular Genitive Singular Nominative Plural Genitive Plural
Masculine and Feminine Ends with a vowel or with -ín (other than muinín and muirín (meaning clann) which are in the second declension), e.g., acra, cailín, oibrí, trá. Does not change the genitive. Ends with -(a)í, -(e)anna, -(i)te, -(i)the, -nna, -nna and the form is completely the same as in the plural, e.g., acraí, cailíní, oibrithe, tránna.
The Fifth Declension
Gender Nominative Singular Genitive Singular Nominative Plural Genitive Plural
Feminine, except a few are Masculine Ends with -il, -in, -ir or with a vowel, e.g., athair, cabhail, cáin, fiche. Ends with a broad consonant, e.g., athar, cabhlach, cánach, fichead. Ends with -(e)acha, -idí, -na, -ne and the form is completely the same as in the plural, e.g., aithreacha, cabhlacha, cánacha, fichidí.

Note: As mentioned in 2.1.2, the form is the same in the Nominative Case, the Accusative Case and the Dative Case and all of them are included under the title Nominative.

2.2 The First Declension

2.2.1 The Singular

This declension includes most of the masculine nouns ending in a broad consonant in the nominative singular. The nouns in the first declension are all masculine.

2.2.2 The Genitive Singular

  1. In the genitive singular, the last consonant is palatalized, e.g., bord, boird; nuachtán, nuachtáin.

  2. The changes under 2.1.4 apply with the palatalization, but -ia- is not changed to -éi- in these nouns: Brian, Briain; cliant, cliaint; fiar, fiair; giar, giair; rian, riain; srian, sriain_; and trian, triain.

  3. mac is changed to mic in the genitive singular and in the genitive plural.

  4. In the genitive singular, -ea- is changed to -i-, e.g., breac, bric; cuireadh, cuiridh; leiceann, leicinn; other than with certain monosyllabic nouns, e.g., each, eich.

2.2.3 The Vocative Singular

  1. The form is usually the same in the vocative singular as in the genitive singular, e.g., a Chorcaígh, a mhic, a Sheáin.

  2. However, it is not customary to inflect in the vocative singular:

    1. on collective names, e.g., a chomhthionól; a phobal;

    2. on nouns used with a metaphorical meaning or as proper names, e.g., a cheann cipín; a chumann; a ghrá geal; a rós geal; a rún; a stór;

    3. on nouns that have a definite genitive subject, e.g., a Chléireach na Dála; a fhear an tí; a scáthán an chirt; a shólás na ndobrónach;

    4. on multi-word official titles, e.g., a Cheann Comhairle; a Oifigeach Ealaíon; a Cheann Scoile.

2.2.4 The Plural

There are both weak plurals and strong plurals in this declension. The nouns that palatalize the final consonant are weak plurals, e.g., amhrán; amhráin; or have -a with them without other changes, e.g., nod; noda; úll; úlla; in the genitive plural. All the other nouns are strong plurals.

Note that the First Declension pattern appears in the genitive singular column in the following tables, namely, that the final consonant is palatalized and -(e)ach is changed to -(a)igh.

  1. Strong Plurals

    Table 2F Strong Plurals in the First Declension — Examples
    Strong Plural Classes Singular Plural
    Nominative Genitive Every Case
    Nouns ending in -ta, -tha in the singular
    Most of the monosyllabic nouns in which there is a long vowel (or diphthong) and end with -l, -n (but not -ll, -nn) in the nominative singular. -tha is put in the plural with occasional nouns ending with -r (but not -rr) in the nominative singular.
    		 braon braoin braonta
    fál fáil fálta
    glór glóir glórtha
    líon lín líonta
    pór póir pórtha
    tuar tuair tuartha
    Nouns ending with -aí, -i in the plural
    Certain monosyllabic nouns ending with -ch, and some in -dh, in the nominative singular, as with some other nouns.
    		 árthach árthaigh árthaí
    cladach cladaigh cladaí (gen. pl. cladach)
    cúram cúraim cúraimí
    daichead daichid daichidí
    margadh margaidh margaí
    Nouns ending with -taí, -thaí in the plural aonach aonaigh aontaí
    dearcadh dearcaidh dearcthaí
    toradh toraidh torthaí
    Nouns ending with -anna in the plural cás cáis cásanna
    praghas praghais praghsanna
    saghas saghais saghsanna
    Nouns ending with -e in the plural and syncopated bóthar bóthair bóithre
    doras dorais doirse
    uasal uasail uaisle
    Nouns ending with -(e)acha in the plural cineál cineáil cineálacha
    coinníoll coinníll coinníollacha
    tobar tobair toibreacha
    Nouns ending with -te in the plural claíomh claímh claimhte
    muileann muilinn muilte
    smaoineamh smaoinimh smaointe
    Miscellaneous nouns breitheamh breithimh breithiúna
    briathar briathair briathra
    gníomh gnímh gníomhartha
    scaitheamh scaithimh scaití

  2. Weak Plurals

    Table 2G Weak Plurals in the First Declension — Examples
    Weak Plural Classes Singular Plural
    Nominative Genitive Nominative Genitive
    Nouns that get narrowed in the nominative plural amhrán amhráin amhráin amhrán
    beithíoch beithígh beithígh beithíoch
    foirgneamh foirgnimh foirgnimh foirgneamh
    iasc éisc éisc iasc
    Nouns ending in -a in the nominative plural bruach bruaigh bruacha bruach
    ceap cip ceapa ceap
    giall géill gialla giall
    úll úill úlla úll

  3. The Vocative Plural

    The vocative plural form is the same as the nominative plural except in the weak plurals. Normally, -a is added to the form inf the nominative singular of those nouns to form the vocative plural, e.g., Corcaíoch, a Chorcaíocha; fear, a fheara; Gael, a Ghaela.

2.3 The Second Declension

2.3.1 The Singular

Nouns in this declension end with a consonant, broad or slender, in the nominative singular. They are all feminine other than im and sliabh.

2.3.2 The Genitive Singular

  1. An -e is put with the nominative singular and if it ends with a broad consonant, it is palatalized, e.g., bróg, bróige; coill, coille; earr, eirre; except with polysyllabic nouns ending with -(e)ach.

  2. When polysyllabic nouns end with -(e)ach, -(a)í is made from -(e)ach, e.g., scornach, scornaí; cailleach, caillí.

  3. The palatalization changes mentioned in 2.1.4 apply to the nouns as follows:

    1. -ea- to -ei-, e.g., beach, beiche (-ea- is changed to -i- in a monosyllabic noun, e.g., beann, binne; cearc, circe; and in the unaccented syllable of the polysyllabic noun, e.g., bruinneall, bruinnille; ficheall, fichille); and

    2. -ia- to -i- in the word scian, scine.

2.3.3 The Dative Singular

There are two forms of the dative singular when nouns end with a broad consonant:

  1. one form is the same as the nominative singular;

  2. a distinct old form used only in well-established expressions, e.g., cur i gcéill; cur dá chois; airgead ar láimh; bolg le gréin; imithe le gealaigh; cur de láimh; faoi bhois an chait; bíonn a chroí ar a bhois i gcónaí aige; ar éill; etc.

2.3.4 The Plural

There are both weak plurals and strong plurals in this declension.

Note that the pattern of the Second Declension is seen in the genitive singular column in the following tables. That is, the genitive singular ends with -e and the final consonant is palatalized if it is a broad consonant, and for polysyllabic nouns ending in -each, -each is changed to -(a)í.

  1. Strong Plurals

    Table 2H Strong Plurals in the Second Declension — Examples
    Strong Plural Classes Singular Plural
    Nominative Genitive Every Case
    Nouns ending in -a in the plural and syncopated, whose vowels are broadened or exchanged dabhach daibhche dabhcha
    roinn roinne ranna
    scian scine sceana
    Nouns ending in -(e)anna in the plural áit áite áiteanna
    blaosc blaoisce blaoscanna
    im ime imeanna
    Nouns ending in -í in the plural
    Polysyllabic nouns ending in a slender consonant in the nominative singular.
    		 abairt abairte abairtí
    cáipéis cáipéise cáipéisí
    earráid earráide earráidí
    Nouns ending in -(e)acha in the plural
    Monosyllabic nouns, and polysyllabic nouns ending in a slender consonant in the nominative singular (other than iníon which ends on a broad consonant).
    		 bainis bainise bainiseacha
    iall éille iallacha
    iníon iníne iníonacha
    maidin maidine maidineacha
    Nouns ending in -ta in the plural
    Some monosyllabic nouns ending in a broad -l or -n in the nominative singular.
    		 buíon buíne buíonta
    grian gréine grianta
    steall steille steallta
    Nouns ending in -te in the plural
    The occasional noun ending in a slender -l or -n in the nominative singular.
    		 aill aille aillte
    bléin bléine bléinte
    linn linne linnte
    Nouns ending in -e in the plural and that are syncopated caingean caingne caingne
    coinneal coinnle coinnle
    foireann foirne foirne
    maighean maighne maighne
    Miscellaneous nouns culaith culaithe cultacha
    gualainn gualainne guaillí
    sliabh sléibhe sléibhte
    uair uaire uaireanta

  2. Weak Plurals

    Table 2I Weak Plurals in the Second Declension — Examples
    Weak Plural Classes Singular Plural
    Nominative Genitive Nominative Genitive
    Monosyllabic and polysyllabic nouns ending in a broad consonant in the nominative singular and have a -a added in the nominative plural and no other changes amharclann amharclainne amharclanna amharclann
    beach beiche beacha beach
    dallóg dallóige dallóga dallóg
    gealach gealaí gealacha gealach
    girseach girsí girseacha girseach
    maighdean maighdine maighdeana maighdean
    Nouns that are broadened and end in -a in the nominative plural cill cille cealla ceall
    deoir deoire deora deor
    ealaín ealaíne ealaíona ealaíon
    rinn rinne reanna reann
    The occasional noun ending in a slender consonant in the nominative singular and ending in -e in the nominative plural ainimh ainimhe ainimhe aineamh
    dúil dúile dúile dúl
    glúin glúine glúine glún
    súil súile súile sú

2.4 The Third Declension

2.4.1 The Singular

  1. This declension has the polysyllabic nouns ending in -áil, -aíl, -cht, -éir, -eoir, -irt, -óir, -úil, -úint, -úir (other than country names that are in the second declension, e.g., an Ailgéir, an Bhrasaíl, an Iodáil).

  2. This declension also has some nouns ending in a consonant, broad or slender, in the nominative singular. For these nouns, the genitive singular ends with -a and the final consonant is broadened if necessary, e.g., buachaill, buachalla; gleann, gleanna (see 2.1.5).

2.4.2 The Genitive Singular

  1. As with in (b) above, the genitive singular ends with -a.

  2. It is customary to change -io- to -ea- in the genitive singular for monosyllabic nouns, e.g., crios, creasa; lios, leasa; but not cion (meaning coir, EN: crime), ciona.

  3. The -t is dropped in the genitive singular from nouns ending in -int, e.g., oiliúint, oiliúna (with these exceptions cogaint, coganta; cosaint, cosanta; seachaint, seachanta). The -th- is turned to -t when nouns end in -irt, e.g., imirt, imeartha.

2.4.3 The Plural

There are both weak plurals and strong plurals in this declension.

Note that the pattern of the Third Declension is seen in the genitive singular column in the following table. That is, the genitive singular ends with -a and the last consonant is broadened if is a slender consonant.

  1. Strong Plurals

    Table 2J Strong Plurals in the Third Declension — Examples
    Strong Plural Classes Singular Plural
    Nominative Genitive Every Case
    Nouns ending in -(a)í in the plural
    Polysyllabic nouns (masculine other than a few, e.g., altóir, seanmóir) ending in -éir, -eoir, -óir, -úir, and polysyllabic nouns (feminine other than few, e.g., bunreacht, comhlacht, complacht, gnólacht) ending in -cht, -irt, -úint in the nominative singular.
    		 athnuachan athnuachana athnuachaintí
    bagairt bagartha bagairtí
    báicéir báicéara báicéirí
    beannacht beannachta beannachtaí
    dlíodóir dlíodóra dlíodóirí
    dochtúir dochtúra dochtúirí
    eisiúint eisiúna eisiúintí
    múinteoir múinteora múinteoirí
    Nouns ending in -(e)anna in the plural
    Polysyllabic masculine nouns (other than some that are feminine, e.g., cuid, dleacht, troid, uaim).
    		 droim droma dromanna
    rang ranga ranganna
    troid troda troideanna
    Nouns ending in -a in the plural and syncopated, broadened or exchanged vowels feadhain feadhna feadhna
    gamhain gamhna gamhna
    slios sleasa sleasa
    Nouns ending in -acha in the plural
    Polysyllabic feminine nouns ending in a slender -l, -n or -r (exceptions: anam, anama, anamacha; úim, úma, úmacha) in the nominative singular.
    Note that this is also how the genitive singular of a noun ending in -aíl is formed, e.g., feadaíl, feadaíola; sceamhaíl, sceamhaíola.
    		 admháil admhála admhálacha
    barúil barúla barúlacha
    fíniúin fíniúna fíniúnacha
    onóir onóra onóracha
    Nouns ending in -ta in the plural
    Monosyllabic nouns ending in -l or -n that is broad (masculine) or slender (feminine) in the nominative singular.
    		 cion (meaning coir) ciona cionta
    feoil feola feolta
    gleann gleanna gleannta
    Nouns ending in -te in the plural cluain cluana cluainte
    móin móna móinte
    táin tána táinte
    Miscellaneous Nouns anacair anacra anacraí
    buachaill buachalla buachaillí
    conradh conartha conarthaí
    maitheas maitheasa maitheasaí
    roth rotha rothaí

  2. Weak Plurals

    Table 2K Weak Plurals in the Third Declension — Examples
    Weak Plural Classes Singular Plural
    Nominative Genitive Nominative Genitive
    Miscellaneous nouns béas béasa béasa béas
    dreas dreasa dreasa dreas
    mionn mionna mionnaí mionn
    tréad tréada tréada tréad
    treas treasa treasa treas

2.5 The Fourth Declension

2.5.1 The Singular

  1. This declension has the masculine nouns ending in -ín, diminutives ending in -ín, the majority of the nouns ending in a vowel, and a small number of other nouns.

  2. Occupational nouns ending in -(a)í or -aire are also masculine, e.g., ceannaí, cócaire.

  3. Abstract nouns ending in -e and formed from an adjective are feminine, e.g., airde, gile, saoirse.

2.5.2 The Genitive Singular

  1. Nouns of this declension do not undergo any change in the genitive singular.

  2. The diminutive -ín normally is feminine if the original word is a common feminine word. There are exceptions, e.g., paidir (fem.), paidrín (masc.); toit (fem.), toitín (masc.). However, all diminutives are declined as masculine nouns in the genitive and vocative singular, e.g., an bheainín bheag, teach an bheainín bhig, a bheainín bhig.

  3. There are some nouns in this Declension that do not have any plural, e.g., cruach (meaning miotal (EN: metal)), dóthain, gorta, lucht (meaning daoine (EN: people)), oiread, tobac.

2.5.3 The Plural

The vast majority of the nouns in this declension have strong plurals.

Note that the Fourth Declension’s pattern is shown in the singular column in the table below. That is, the form of the genitive singular is the same as the form of the nominative plural.

  1. Strong Plurals

    Table 2L Strong Plurals in the Fourth Declension — Examples
    Strong Plural Classes Singular Plural
    Every Case Every Case
    Nouns ending in -(a)í in the plural
    Nouns ending in -a, -e, -ín in the singular.
    		 altra altraí
    báidín báidíní
    fáinne fáinní
    Nouns ending in -te in the plural
    Occasional nouns ending in -le, -ne in the singular.
    		 baile bailte
    sloinne sloinnte
    tine tinte
    Nouns ending in -(i)the in the plural
    Nouns ending in -(a)í, -aoi, -é in the singular (-í- is not shortened in the monosyllabic nouns, other than ní, nithe).
    		 ainmhí ainmhithe
    draoi draoithe
    giúiré giúiréithe
    rí ríthe
    Nouns ending in -nna in the plural
    Nouns ending in -á, -ao, -eá, -eo, -ia, -ó, -ogha, -ú, -ua in the singular.
    		 bogha boghanna
    ceo ceonna
    cnó cnónna
    cú cúnna
    grua gruanna
    íomhá íomhánna
    lao laonna
    meá meánna
    nia nianna
    Some nouns ending in a consonant in the singular and have -(e)anna added in the plural and no other changes bus busanna
    seic seiceanna
    téacs téacsanna
    Occasional nouns ending in -ite in the plural comhrá comhráite
    cró cróite
    crú crúite
    rá ráite
    slua sluaite
    Miscellaneous nouns achainí achainíocha
    airí airíonna
    aithne aitheanta
    aturnae aturnaetha
    bó ba (gen. pl. bó)
    cine ciníocha
    claí claíocha
    duine daoine
    gabha gaibhne
    gnó gnóthaí
    oíche oícheanta
    slí slite
    teanga teangacha

    Note: Note that in the following nouns, which do not necessarily have a plural form, also belong to this declension: cruach (meaning miotal (EN: metal)), dóthain, gorta, iomad, lucht (meaning daoine (EN: people)), oiread, tobac; along with some personal names, e.g., Cáit, Liam, Pilib, Siobhán, Uileag.

2.6 The Fifth Declension

2.6.1 The Singular

  1. The majority of the nouns in this declension are feminine.

  2. This declension also has some nouns ending in slender consonants or a vowel in the nominative singular and on a broad consonant (-ch, -d, -(n)n, -r) in the genitive singular.

2.6.2 The Plural

The vast majority of nouns in this declension have strong plurals.

Note that the pattern of the Fifth Declension is shown in the genitive singular column of the following table. That is, the genitive singular ends with broad consonants -ch, -d, -(n)n, -r (other than rare exceptions, e.g., Nollaig, Nollag).

  1. Strong Plurals

    Table 2M Strong Plurals in the Fifth Declension — Examples
    Strong Plural Classes Singular Plural
    Nominative Genitive Every Case
    Nouns ending in -(e)acha in the plural
    Feminine nouns ending in -il, -in, -ir in the nominative singular (exceptions: siúr, siúrach). In the genitive singular, the final consonant of a monosyllabic noun is broadened, and other nouns do not undergo syncopation, and an -ach is added (exceptions: cathaoir, cathaoireach).
    Polysyllabic nouns are syncopated if they have a short vowel in the final syllable and -(e)ach is added.
    		 cathair cathrach cathracha
    draein draenach draenacha
    litir litreach litreach
    rial rialach rialacha
    traein traenach traenacha
    treoir treorach treoracha
    triail trialach trialacha
    uimhir uimhreach uimhreacha
    The occasional nouns that ends in -inn, -ir in the nominative singular, broadened in the genitive singular and ending in -(e)acha in the plural.
    (Exceptions: bráthair, bráthar, bráithre.)
    		 abhainn abhann aibhneacha
    máthair máthar máithreacha
    teorainn teorann teorainneacha
    Nouns ending in -na, -ne in the plural
    Feminine nouns ending in a vowel in the nominative singular and in -n in the genitive singular (exceptions: díle, díleann, dílí; lacha, lachan, lachain (gen. sg. lachan)).
    		 ceathrú ceathrún ceathrúna
    comharsa comharsan comharsana (gen. pl. comharsana)
    ionga iongan ingne
    leite leitean —
    monarcha monarchan monarchana
    pearsa pearsan pearsana (gen. pl. pearsan)
    Nouns ending in -idí in the plural
    The occasional masculine noun ending in -d in the genitive singular.
    Note that daichead (daichid, daichidí) belongs to the first declension.
    		 fiche (dat. sg. fichid) fichead fichidí
    tríocha tríochad tríochaidí
    ceathracha ceathrachad ceathrachaidí
    caoga caogad caogaidí
    seasca seascad seascaidí
    seachtó seachtód seachtóidí
    ochtó ochtód ochtóidí
    nócha nóchad nóchaidí
    Miscellaneous nouns bráid brád bráide
    cara carad cairde
    caora caorach caoirigh (gen. pl. caorach)
    Éire (dat. sg. Éirinn) Éireann —
    namhaid namhad naimhde
    Nollaig Nollag Nollaigí

2.7 Irregular Nouns

The inflections of the following nouns do not correspond to any of the declensions:

Table 2N Irregular Nouns — Examples
Singular Plural
Nominative Genitive Every Case
bean mná mná (gen. pl. ban)
deirfiúr deirfiúracha deirfiúracha
deoch deochanna deochanna
dia déithe déithe
lá lae laethanta
leaba leapa leapacha
mí míosa míonna
olann olla olanna (gen. pl. olann)
talamh (masc.) talaimh (masc.)
talún (fem.) 		tailte
teach tí tithe

Note: Note that a distinct old form of the word lá is used in the old phrase ar athló, e.g., Tá an Dáil ar athló.