This is Chapter 4 of the unofficial translation of An Caighdeán Oifigiúil based off of the 2017 version. You can find all other chapters here.
4.1 Attributive Adjectives
4.1.1 Adjectives are split into three declensions.
4.1.2 An adjective is only declined when it is used as an attributive adjective.
4.1.3 The form of an attributive adjective depends on the gender, case and number of the noun it is qualifying and on the declension of the adjective itself. See Chapter 9 for rules regarding the use of adjectives with numbers.
4.2 The Gender, Case and Number of Attributive Adjectives
4.2.1 Attributive adjectives agree with their noun with regards to gender, case and number. In the case of a series of nouns, the adjective agrees with the final one, e.g. mná agus fir ghnaíúla; peann, páipéar agus bileog ghorm. In the case of a series of adjectives after a single noun, each adjective agrees with the noun, e.g. ailt shuimiúla thábhachtacha fhada.
| Tháinig na mná agus na fir ghnaíúla isteach. |
| Tháinig na fir agus na mná gnaíúla isteach. |
| Bhí sciorta, cóta agus scaif ghorm uirthi. |
| Tá cait mhóra fhiáine i ngairdín na n-ainmhithe. |
4.2.2 (a) In the singular:
(i) for masculine nouns, the qualifying adjective is not lenited, e.g. an fear beag, ag an bhfear beag; except in the vocative case and the genitive case, e.g. a fhir bhig; hata an fhir bhig;
(ii) if the Lenition System (see 1.7) is being used, the adjective qualifying a masculine noun in the dative case is lenited if it is accompanied by the article, e.g. ag an fhear bheag.
(b) For singular feminine nouns, the qualifying adjective is lenited in all cases, e.g. an bhean bheag; a bhean bheag; ag an mbean bheag; except for the genitive, e.g. hata na mná bige.
4.2.3 An explanation is given in Chapter 9 about attributive adjectives when the noun they qualify is preceded by a number.
4.2.4 Lenition of Attributive Adjectives in the Singular
An adjective is either left as it is or lenited based on the gender and case of the noun it is qualifying. The cases are shown in the table below. See the discussion on the declension of adjectives (4.3) for more information on form changes (other than lenition) to the adjective itself.
| Case | Masculine Singular Noun | Feminine Singular Noun |
| Nominative and Accusative | no lenition: an fear beag | lenition: an bhean bheag |
| Vocative | lenition: a fhir bhig | lenition: a bhean bheag |
| Dative* | no lenition: ar an bhfear beag | lenition: ar an mbean bheag |
| Genitive | lenition: clann an fhir bhig | no lenition: clann na mná bige |
*However, see 1.7 for the Lenition System.
4.2.5 Lenition of Attributive Adjectives in the Plural
In the plural, the initial consonant of an adjective is lenited if the noun ends in a slender consonant, as in the table below (see also 10.3.1).
| Lenition | No Lenition |
| Nouns ending in a slender consonant in the plural | Nouns ending in a vowel or broad consonant in the plural |
| na báid fhada na costais shonracha na foirgnimh bhreátha na fir bheaga na goirt mhóra na héisc gheala na húdair cháiliúla na nóiméid dheireanacha na pinn ghorma na sparáin theanna | na cailíní cliste na doirse móra na páirceanna móra na táilliúirí costasacha clanna na mban cáiliúil clanna na bhfear beag éifeacht na bhforálacha forlíontacha méid na bhfuinneog cearnach obair na ngaibhne dubha seirbhísí na leabharlann poiblí |
4.3 Declension of Adjectives
4.3.1 The nominative, accusative and dative singular forms of an adjective are all identical, as are the nominative, accusative and dative plural.
4.3.2 In the genitive plural:
(a) if the noun has a strong plural, the form of the adjective is the same as the nominative plural:
| Nominative plural | Is maith liom na filí móra. |
| Genitive plural | Is maith liom dánta na bhfilí móra. |
(b) if the noun has a weak plural, the form of the adjective is the same as the nominative singular:
| Nominative singular | Foilsíonn an t-údarás áitiúil tuarascáil gach bliain. |
| Genitive plural | Foilsíodh tuarascálacha na n-údarás áitiúil. |
4.3.3 (a) An adjective in the masculine vocative is not lenited nor inflected if the noun is a pet name or has a metaphorical meaning.
| Cén chaoi a bhfuil tú, a athair beag? |
| A dheartháir dílis, bhí a fhios agam go maith gur tú a bhí ann. |
| A bhéal cumhra, nach muid a bheidh sásta le chéile. |
| Conas atá tú, a mhac bán? |
(b) The first letter of an adjective is lenited, however, if it is preceded by a feminine noun.
| Cad é mar atá tú inniu, a thaisce mhilis? |
| A mháthair bheag, ní bheidh deireadh go deo le do chuid oibre. |
4.3.4 Adjectives are not inflected after female baptismal names, e.g. Máire Mhór, teach Mháire Mhór.
4.3.5 No inflection, nor initial mutation, is made to adjectives following, or being used as, an adverb, such as cuibheasach, sách, measartha, réasúnta, etc.
| Is bean measartha saibhir í. |
| Mná measartha saibhir is ea iad. |
| Fir sách ard is ea iad. |
| Páistí réasúnta ciúin is ea iad. |
| Maidin sách fuar a bhí ann. |
| Bliain cuibheasach tirim atá uainn. |
4.3.6 An adjective following the emphatic particle an- is not inflected.
| Is daoine an-bhreá iad. |
| Déanfar na gnéithe an-tábhachtach sin a mheas. |
| Ní páistí an-chiúin iad. |
4.3.7 No inflection, nor initial mutation, is made to adjectives that are part of a multi-word adjectival phrase, e.g. athnuachan saor in aisce; tuarascáil cothrom le dáta.
| Is bean mór le rá í i réimse na heolaíochta. |
| Ba é údar na tuarascála cothrom le dáta a thug an cur i láthair. |
4.3.8 The genitive singular form is determined separately by each declension.
4.4 The First Declension
This declension is comprised of adjectives that end in a consonant, broad or slender, except those ending in -úil and some ending in -ir (see 4.5).
4.4.1 The Genitive Singular Form
(a) Masculine
(i) If the adjective ends in a broad consonant, it is slenderised as happens with nouns in the First Declension (see 2.2.2).
| Cár fhág sé hata an fhir mhóir? |
| Caithfear coinníollacha an chonartha bhuain a léamh go cúramach. |
| Léigh sé leabhar an imreora chlúitigh. |
(ii) Monosyllabic adjectives ending in -ch(t) (except bocht) are not inflected in the masculine genitive singular, e.g. beacht, caoch, déach, fliuch, lách, moch, nocht.
| Bhí orthu an fhéile a chur ar siúl ag deireadh an tsamhraidh fhliuch. |
| Tá na páistí i rang an mhúinteora bheacht i mbliana. |
| Goideadh ba an fheirmeora bhoicht. |
(iii) If the adjective ends in a slender consonant or -íoch, it is not inflected.
| Ba mhaith liom labhairt le tuismitheoirí an bhuachalla chiúin. |
| Bhí gach duine i bhfabhar an fheachtais thionsclaíoch. |
(iv) Monosyllabic adjectives ending in a double consonant (except dall, donn, fionn) are not inflected in the masculine genitive singular, e.g. cearr, corr, gann, gearr, mall, teann, toll.
| Tá praghas an bhia ghann ag ardú gach lá. |
| Chuir costas an turais ghearr iontas orthu. |
| Bhí boladh an aráin dhoinn ar fud an tí. |
(v) The following monosyllabic adjectives are not inflected in the masculine genitive singular: amh, cúng, deas (with the meaning ‘kind’), leamh, mear, seang, searbh, tearc, tiubh, trom, tur.
(b) Feminine
(i) An -e is added to the final consonant, which is slenderised if it is broad, e.g. gorm, goirme; maith, maithe, as is done to nouns in the Second Declension (see 2.3.2).
| Féach ar áilleacht na spéire goirme. |
| Cé hé údar na tuarascála maithe? |
(ii) Adjectives ending in -(e)ach have this changed to -(a)í, e.g. aisteach, aistí; iontach, iontaí; as is done to nouns in the Second Declension (see 2.3.2).
| Tá guth na caillí aistí le cloisteáil ar an taifead. |
| Thaitin téama na haiste iontaí liom. |
(iii) Adjectives ending in -íoch have this changed to -íche, e.g. eacnamaíoch, eacnamaíche.
| Cathain a bhraithfimid deireadh na géarchéime eacnamaíche? |
| Is maith an rud é fás na hearnála tionsclaíche. |
(iv) see Chapter 2 for the comprehensive description of vowel changes.
4.4.2 The Vocative Singular Form
The vocative singular form is the same as the nominative singular, except for adjectives whose final consonant is slenderised in the masculine genitive singular. In those cases, the masculine vocative singular is usually the same as the masculine genitive singular, e.g. a fhir mhóir; cóta an fhir mhóir.
4.4.3 The Plural Form – All Cases
An -a is added to adjectives ending in a broad consonant, and -e to adjectives ending in a slender consonant, and some particular adjectives undergo syncope (but see weak plurals in the genitive plural, 4.3.2(b)).
| Cá bhfuil na peileadóirí clúiteacha? |
| Foilseofar na haistí maithe san iris bhliantúil. |
| Bhí na daoine uaisle i láthair inné. |
4.4.4 Syncope in the Singular and Plural
Syncope occurs in the feminine genitive singular and in all plural cases for the adjectives in the table below, amongst others, apart from the forms in parentheses.
| Nominative Singular | Feminine Genitive Singular | Plural |
| álainn | áille | áille |
| aoibhinn | aoibhne | aoibhne |
| bodhar | (bodhaire) | bodhra |
| daibhir | daibhre | daibhre |
| daingean | daingne | daingne |
| deimhin | deimhne | deimhne |
| dílis | dílse | dílse |
| doilbhir | doilbhre | doilbhre |
| domhain | doimhne | doimhne |
| folamh | foilmhe | folmha |
| íseal | ísle | ísle |
| láidir | láidre | láidre |
| milis | milse | milse |
| ramhar | raimhre | ramhra |
| righin | righne | righne |
| saibhir | saibhre | saibhre |
| sleamhain | (sleamhaine) | sleamhna |
| soilbhir | soilbhre | soilbhre |
| uasal | uaisle | uaisle |
4.5 The Second Declension
This declension is comprised of adjectives that end in -úil, as well as adjectives ending in -ir, e.g. cóir, deacair, socair.
4.5.1 The Form of the Genitive Singular
(a) Masculine
The adjectives in this declension take no inflection.
| Cá bhfuil athair an fhir chóir? |
| Léigh mé tús an leabhair shuimiúil. |
(b) Feminine
The final consonant becomes broad, and an -a is added to it.
| Cá bhfuil athair na mná cáiliúla? |
| Léigh mé tús na haiste deacra. |
4.5.2 Plural Form – All Cases
(a) The final consonant becomes broad and an -a is added to it, as in the feminine genitive singular (but see weak plurals in the genitive plural, 4.3.2(b)).
| Cá bhfuil na fir cháiliúla agus na mná dathúla? |
| Léigh mé na dánta suimiúla inné. |
(b) Syncope occurs for deacair, deacra; socair, socra in the genitive singular and the plural.
4.6 The Third Declension
4.6.1 This declension is comprised of adjectives ending in a vowel, e.g. cliste, cróga.
4.6.2 No adjectives in this declension are inflected, apart from two: breá and te. Breá becomes breátha in the feminine genitive singular and in the plural, and te becomes teo in the plural (but see weak plurals in the genitive plural, 4.3.2(b)).
| Nominative singular | Tine bhreá the a bhí ann. |
| Genitive singular | Dath na tine breátha te. |
| Nominative plural | Lasadh na tinte breátha teo. |
4.7 Summary of Declensions of Adjectives
| Masculine Singular Noun | |||
| Case | First Declension | Second Declension | Third Declension |
| Nominative | an fear beag an peileadóir clúiteach an buachaill ciúin | an fear misniúil an duine cóir an t-óstóir flaithiúil | an cóta buí an garda cróga an duine cuí |
| Vocative | a fhir bhig a pheileadóir chlúitigh a bhuachaill chiúin | a fhir mhisniúil a dhuine chóir a óstóir fhlaithiúil | a gharda chróga a dhuine chuí a fhir chliste |
| Dative* | ag an bhfear beag don pheileadóir clúiteach leis an mbuachaill ciúin | don fhear misniúil chuig an duine cóir ón óstóir flaithiúil | ar an gcóta buí ag an ngarda cróga leis an duine cuí |
| Genitive | caipín an fhir bhig ainm an pheileadóra chlúitigh rang an bhuachalla chiúin | eachtra an fhir mhisniúil clann an duine chóir comhairle an óstóra fhlaithiúil | úinéir an chóta bhuí thar ceann an duine chuí guth an gharda chróga |
*but see 1.7 The Lenition System.
| Feminine Singular Noun | |||
| Case | First Declension | Second Declension | Third Declension |
| Nominative | an bhean bheag an bhó álainn an mháthair imníoch | an bhean ghairmiúil an tuairisc mhíosúil an aiste dheacair | an éide ghalánta an aiste ghonta an mhí fhada |
| Vocative | a bhean bheag a aintín álainn a mháthair imníoch | a bhean ghairmiúil a aintín fhlaithiúil a mháthair chóir | a bhean chróga a aintín ghalánta a mháthair chróga |
| Dative | don bhean bheag ag an aintín álainn leis an máthair imníoch | don bhean ghairmiúil sa tuairisc mhíosúil san aiste dheacair | ar an éide ghalánta san aiste ghonta den mhí fhada |
| Genitive | teach na mná bige peata na máthar imníche ceol na haintín áille | maoin na mná gairmiúla fad na tuairisce míosúla teideal na haiste deacra | luach na héide galánta údar na haiste gonta deireadh na míosa fada |
| Masculine Plural Noun | |||
| Case | First Declension | Second Declension | Third Declension |
| Nominative | na fir bheaga na peileadóirí clúiteacha na buachaillí ciúine | na leabhair shuimiúla na daoine córa na páistí flaithiúla | na cótaí buí na daoine cuí na gardaí cróga |
| Vocative | a fheara beaga a pheileadóirí clúiteacha a bhuachaillí ciúine | a fheara misniúla a dhaoine córa a pháistí flaithiúla | a dhaoine cuí a fheara cliste a ghardaí cróga |
| Dative | ar na fir bheaga ag na peileadóirí clúiteacha leis na buachaillí ciúine | do na fir mhisniúla leis na daoine córa ó na páistí flaithiúla | ar na cótaí buí leis na daoine cuí do na gardaí cróga |
| Genitive | caipíní na bhfear beag bróga na bpeileadóirí clúiteacha rang na mbuachaillí ciúine | bás na bhfear misniúil clann na ndaoine córa airgead na bpáistí flaithiúla | úinéirí na gcótaí buí ar son na ndaoine cuí hataí na ngardaí cróga |
| Feminine Plural Noun | |||
| Case | First Declension | Second Declension | Third Declension |
| Nominative | na mná beaga na haintíní áille na máithreacha imníocha | na mná gairmiúla na haintíní córa na hiníonacha flaithiúla | na héidí galánta na haistí gonta na míonna fada |
| Vocative | a mhná beaga a aintíní áille a mháithreacha imníocha | a mhná gairmiúla a aintíní córa a iníonacha flaithiúla | a mhná galánta a iníonacha cróga a aintíní cliste |
| Dative | do na mná beaga ag na haintíní áille leis na máithreacha imníocha | do na mná gairmiúla leis na haintíní córa ó na hiníonacha flaithiúla | leis na héidí galánta sna haistí gonta de na míonna fada |
| Genitive | teach na mban beag ceol na n-aintíní áille deifir na máithreacha imníocha | pá na mban gairmiúil clann na n-aintíní córa airgead na n-iníonacha flaithiúla | luach na n-éidí galánta údair na n-aistí gonta tús na míonna fada |
4.8 Degrees of Comparison of Adjectives
4.8.1 (a) The comparative and superlative forms of an adjective are usually the same as its feminine genitive singular, e.g. ard, airde; breá, breátha; cóir, córa; dathúil, dathúla; deacair, deacra; díreach; dirí.
| Faigh an luach is airde air. |
| Is í Ciara an cailín is dathúla sa rang. |
| An rud is deacra faoin bhfilíocht, a léamh mar is cóir. |
(b) The comparative and superlative forms of an adjective ending in -íoch are also the same as its feminine genitive singular, e.g. buíoch, buíche; débhríoch, débhríche; imníoch, imníche; impíoch, impíche; taithíoch, taithíche; uathoibríoch, uathoibríche.
| Is iadsan na daoine is imníche sa tír. |
| Is eisean is taithíche ar an obair seo. |
| Cuirfear an córas is uathaoibríchea i bhfeidhm. |
4.8.2 Some adjectives have irregular forms, e.g. beag, lú; dócha, dóichí; fada, faide (sia); fogas, foisce; furasta, fusa; gearr, giorra; iomaí, lia; maith, fearr; mór, mó; olc, measa; te, teo.
| Is é Rónán an duine is fearr sa rang. |
| Is í an chuimhne is faide (is sia) siar i mo cheann í. |
| Cé acu ceann is mó? |
4.8.3 Forms following dá and a
(a) After dá and a, regardless of whether they have a cataphoric or anaphoric function, it is typical to use a form the same as the comparative, or a form that derives from the comparative or positive form and ends in -acht.
(b) Only a single form is used for the following adjectives: dócha, dóichí; dona, donacht; furasta, fusacht; gearr, giorracht; and for these irregular forms: beag, laghad; fada, fad; iomaí, liacht; maith, feabhas; mór, méad/méid; olc, olcas; tiubh, tiús.
(c) Méid is used instead of méad in certain cases, e.g. dá mhéad airgead a bhí aici, but a mhéid is indéanta le réasún; a mhéid is gá.
| B’aoibhinn liom a áille (a bhinne, a chruinne, a líofa, a réidhe, a shoiléire) a labhair sí. |
| Ní chreidfeá a achrainní (a dhonacht, a olcas, a shleamhaine, a uaigní) a bhí an áit. |
| Fuair sé ardmholadh trína fheabhas a rinne sé an obair. |
| Dá chríonna (dá chróga, dá fheabhas, dá ghlice, dá oilte) é, níor éirigh an gnó leis. |
| Dá dhonacht (dá ghránna, dá leisciúla, dá olcas, dá shuaraí) é, caithfear glacadh leis. |
| Dá mhéad dúil a bhí aici ann, níor cheannaigh sí sa deireadh é. |
4.9 The Possessive Adjective
Since the possessive adjectives mo, do, a (masculine and feminine singular), ár, bhur and a (plural) function as pronouns in the genitive, they are covered in Chapter 8.
4.10 The Demonstrative Adjective
The demonstrative adjectives are seo, sin, siúd and úd. (Although seo, sin and siúd are demonstrative pronouns, it is often that they are referred to as demonstrative adjectives).
| Tá an fear seo tinn. |
| Beidh an buachaill seo ag teacht liom. |
| Is liomsa iad seo. |
| Níl an doras sin dúnta. |
| Síle is ainm don chailín sin. |
| Díoladh a theach siúd inné. |
| Is aige siúd a bhí an t-airgead. |
| An bhfeiceann tú an pháirc úd thall? |
4.11 The Predicative Adjective
A predicative adjective is one that qualifies a noun as a predicate, or as part of a predicate, e.g. Nach deas é?; Tá an aimsir fuar. Predicative adjectives are neither lenited nor inflected.
| Bhí an traein folamh. |
| Bíonn na busanna déanach. |
| An bhfuil an bhean sin saibhir? |
| Beidh an bhainis sin mór. |
4.12 The Verbal Adjective
The verbal adjective functions as a normal adjective. It is used:
(a) as a qualifying adjective, e.g. Is bean phósta í;
(b) as a predicative adjective following the copula, e.g. Ní briste atá sé;
(c) as a predicative adjective following the verb bí describing the state of the object after the action, e.g. Is í atá tugtha don obair;
(d) as a predicative adjective following the verb bí describing the state of the agent after the action, e.g. Táimid beirthe go maith leis an socrú sin.