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    Mutations in present-day Irish

Realisation of the mutations
Palatalisation – depalatalisation
Conditions for the mutations
Prefix D

This module offers information on the realisation of the initial mutations in present-day Irish and the conditions under which they occur. As has been mentioned in the first module of the morphology sub-menu, initial mutation should be viewed together with change to the right margins of words, i.e. palatalisation (of non-palatal bases) and de-palatalisation (of palatal bases). The alternations at the left and right margins of words are a key feature of Irish morphology and frequently occur together, e.g. in noun morphology where they can distinguish gender and case.

Realisation of the mutations

Lenition (seimhiú)

Lenition can only affect certain of the consonant phonemes. These are the following:

From the point of view of initial mutation the distinction palatal/velar is irrelevant: if one consonant of a palatal/velar pair is mutable then so is the other one. Nine of the fifteen consonant pairs of Irish can be subject to lenition. The six that do no lenite can be divided into two groups:

As the second group consists of elements which are themselves the outcome of lenition, the matter is irrelevant. But in the case of the sonorants, the lack of lenition means that grammatical categorie are not formally marked with them. This means, for instance, that a verb which begins in a sonorant will not lenite in the past, e.g. rith sé ‘he ran’, and that a masculine noun beginning in a sonorant will not lenite in the genitive singular, e.g ainm an naoimh ‘the name of the saint’. However, in cases like the latter both the palatalisation at the end of the word and its syntactic position (preceded by an article and a qualifying noun) are sufficient for the genitive to recognised unambiguously.

Lenition is the first and foremost the fricativisation of stops. Two fricatives in Irish – /s/ and /f/ – can also be subject to lenition. The results are irregular in these cases: /s/ lenites to /h/ while /f/ lenites to zero. Due to a shift which took place by the Middle Irish period at the latest, /d/ shifts to a velar fricative.

The irregularities of lenition means that with some consonants the outcome of lenition is homophonous with that of another consonant. This leads to three mergers as follows:

In some dialects the outcome of leniting /m/ – /v/ – may show a degree of nasalisation, but this is subphonemic and hence does not have systemic status.

Historically, there are instances of loanwords (from Anglo-Norman or English) where the initial segment of the word was regarded as lenited and then reversed on borrowing. This applies in particular to /v-/ and /w-/ which appear as /b-/ on borrowing, e.g. baránta ‘waranty’, balla ‘wall’, bigil ‘vigil’, bís ‘vice’.

Because the lenition of /f/ leads to zero, there can be cases where it is uncertain if a word which begins with a vowel is a case of a truly vowel-initial word or one where the initial /f/ has been lenited. This situation must be resolved by children during first language acquisition and the evidence of some words shows that previous generations misinterpreted vowel-initial words as instances of initial lenited /f/ and then ‘restored‘ the unetymological /f/. Such a development lies behind words like fuar (< uar) ‘cold’ and faidhb (< aidhb) ‘problem’.

Nasalisation (urú)

The operation of nasalisation has as its end point the nasalisation of the segment it is applied to. This mutation can only involve one step, however. This means can only voiced segments can mutate to a nasal. A voiceless segment, when ‘nasalised’, undergoes the first step only, i.e. it is voiced. As opposed to lenition, the fricative /s/ cannot be nasalised. Indeed, there is no /z/ phoneme in the sound system of Irish (although it was reported for the now moribund dialect of Cape Clear).

Zero mutation

It is useful in Irish to designate cases where neither lenition nor nasalisation occurs as zero mutation. The lack of a mutation in itself fulfils an important function. Thus the absence of a mutation shows in the nominative singular that a noun is masculine, the opposite gender being marked by lenition: an cruth ‘shape, appearance’, an chuairt ‘visit’.

Palatalisation – depalatalisation

To treat palatalisation and depalatalisation together, one can talk of a feature [palatal] which can have a positive or negative value. The citation forms of words will have a given value for this feature. Citations forms are used for dictionary entries and are generally the shortest forms of the word class in question. The following are common citations forms.

1)   the nominative of nouns
2)   the base form of adjectives
3)   the second person singular imperative of verbs

The value for [palatal] can vary between words. For instance, the right margin of bord ‘table’ has a negative value for [palatal] while cáin ‘tax’ has a positive value. When these nouns occur in the genitive, the values for [palatal] are reversed. Other processes may also be involved, for instance with fifth declension nouns where the right margin changes to [+palatal] in the genitive a suffix is also added: méid na cánach ‘the amount of tax’.

Palatalisation (caolú)

Palatalisation involves changing the final consonant of a word stem from a velar to a palatal point of articulation. This is indicated in writing either by adding an -i before the final consonant or by exchanging an -i for another vowel in this position:

‘a path’
leithead an chosáin
‘the width of the path’
an t-éan miotasach
‘the mythical bird’
na héin fhadghobacha
‘the long-beaked birds’

In this case the syllable bearing vowel remains intact although there is a palatal off-glide to the altered final consonant. This holds for long vowels and a short vowel before the cluster /-xt/ which on palatalisation only changes the final /t/ to a palatal. In other cases of short vowels palatalisation tends to change a stem vowel from a back to a front vowel, for instance a word with the vowel of the SIOC lexical set (when the right margin is [-palatal]) frequently switches to the vowel of the FIOS lexical set when the right margin is [+palatal] (the reason for talking about the vowels in lexical sets is that these can vary across dialects, but there is still a back – front difference between the short vowels).


Nominative Genitive
corp píonta coirp
‘a body’ ‘pains in one’s body’
neart méadú nirt
‘strength’ ‘increase in strength’
mac cailín a mhic
‘son’ ‘his son’s girlfriend’


Base form Comparative
bog boige ‘soft’
mall moille ‘slow’
reamhar reimhre ‘fat’
deas deise ‘nice’

When palatalisation originally arose in the pre-history of Irish it involved only one step, the articulation of a sound in the region of the palate. But in the course of time, various developments took place which complicated the picture. Labial sounds could not become palatal as they would then have lost their labial quality so they developed a short [j], heard on the release of the labial when it underwent the phonological process of palatalisation. This glide can still be heard in a word like fionn ‘fair’. With non-palatal sounds, a [w] glide sometimes developed between the non-palatal and the following sound. This glide is noticeable in northern Irish pronunciations of a word like fáil ‘getting’.

Another development was the vocalisation of palatal sounds in word-final position. This happened in all word which were later written with -(a)igh, e.g. ceannaigh where the final syllable is /i:/. It also happened with the ending -(a)ith and -(a)idh and usually with -(a)-imh. This means that for many words the change of /x/ to /xʲ/ on palatalisation is now a shift from /x/ to /i:/, cf. marcach ‘rider’ ~ ainm an mharcaigh ‘the name of the rider’. In still other cases there is an alternation between schwa and /i:/, again due to an early vocalisation of word final sounds, e.g. culaith ‘suit’ ~ culaithe ‘suit’-GEN.

Velarisation (leathnú)

Velarisation is the mirror image of palatalisation, that is it represents a shift from front to back position of articulation among consonants. Just as with palatalisation it may also effect the quality of the syllable bearing vowel in a stem when this is short, cf. fuil (high front vowel) ‘blood’ ~ fola (low back vowel) ‘blood’-GEN.


feirmeoir talamh an fheirmeora
‘a farmer’ ‘the land of the farmer’
cuid ag fáil a coda
‘share’ ‘getting her share’


cuir ag cur seaca
‘put’ ‘frosting’ (lit.: putting frost-GEN)
socraigh ag socrú cruinnithe éigin
‘arrange’ ‘arranging some meeting or other’

Conditions for the mutations

As a rule citation forms of words are not lenited. There are, however, a small number of words which are permanently lenited.

cheana ‘already’ bhur ‘your’
choíche ‘ever’ dhá ‘two’
chomh ‘as’ dhom ‘for-me’
chun ‘for’ dhuit ‘for-you’
chuig ‘to’ thú ‘you’-SG (in object function)

In the following tables are offered in which the effect of a qualifying element or grammatical category, e.g. case, is specified in term of mutation. L stands for lenition and N for nasalisation. The lists are exemplary and not exhaustive.

1) Possessive pronouns

  Singular   Plural
  masc fem masc + fem
1 mo + L ‘my’   ár + N ‘our’
2 do + L ‘your’-SG   bhur + N ‘your’-PL
3 a + L ‘his’ a + H ‘her’ a + N ‘their’

The label H indicates that the mutating particle triggers a h-prefix, if the following word begins with a vowel, otherwise their is no change (zero mutation). This situation also applies to plural nouns after the article na.

1a) Third person possessive pronoun

a + H: ‘her’ a cairde
a h-anam
‘her friends’
‘her soul’
H=prefix h before vowels. otherwise no change
a + L: ‘his’ a chairde ‘his friends’ L=lenition
a + N: ‘their’ a gcairde ‘their friends’ N=nasalisation

2) Mutation after forms for the article

  Singular   Plural  
  masc. fem. masc. fem.
Common (an) Ø (an) L (na) H (na) H
Genitive (an) L (an) H (na) N (na) N

Vocative (a) L (a) L (a) L (a) L

Conditions for the occurrence of lenition

Lenition with nouns

with masculine nouns in the genitive case

leabhar an mhúinteora ‘the teacher’s book’
fuaim an chloig mhóir (< mór)
‘the sound of the big bell’

with feminine nouns in the common case

an Ghaeilge ‘the Irish language’

Lenition with adjectives

Generally lenition of adjectives follows that of nouns:

teach an fheirimeora shaibhir ‘the house of the rich farmer’ (masculine genitive singular)
an bhean mhisniúil ‘the courageous woman’ (feminine common singular)

Lenition with verbs

with the past tense

Cheannaigh sé carr nua. ‘He bought a new car’

but not the autonmous form

Cailiú anuraidh é. ‘He died last year’, lit. ‘was lost’

with the conditional

Cheannóinn teach nua dá mbeadh an t-airgead agam.
‘I would buy a new house if I had the money’

with the past habitual

Bhíodh sé i mBaile Átha Cliath go minic.
‘He used be in Dublin very often.’

In a verbal environment

1) Relativisers

Lenition in a verbal environment

1) Relativisers

a) gur Dhearbhaigh sé gur shroich siad an taobh eile.
‘that’ ‘He asserted that they reached the other side.’

b) nár Dhearbhaigh sé nár shroich siad an taobh eile.
‘that’-NEG ‘He asserted that they did not reach the other side.’

c) a Na fir a shroich an taobh eile.
‘who’-REL ‘The men who reached the other side.’

When a also occurs before a transitive verbal noun it lenites:

Bhí sé ar tí é a dhéanamh. ‘He was about to do it.’

The element ag which occurs with the same verbal element (in a durative sense) has zero mutation:

Tá sé ag freagairt na ceiste. ‘He is answering the question.’

The further particle which may occur before the verbal noun á acts like a possessive pronoun agreeing with the object from the point of view of mutation:

Bhí siad á bhagairt Bhí siad á bagairt.
‘They were threatening her.’ ‘They were threatening him.’

2) Negativisers

a) Ní dhéanfadh sin cúis.
Neg Past ‘That won’t do.’
b) níor Níor dhúirt mé tada.
Past ‘I didn’t say a thing.’

3) Interrogatives

a) ar Ar dhúirt sé aon rud?
Positive + Past ‘Did he say anything?’
b) cár Cár thug sé an scéal di?
Locative + Past ‘Where did he give her the message?’

4) Conditionalisers

a) Má thitim sé na bac leis.
Positive ‘If I fall don’t bother about it.’
b) murar Murar ghlac sé leis an tairiscint.
Negative + Past ‘If he didn’t accept the offer.’

Conditions for the occurrence of nasalisation

Nasalisation is more regular in its occurrence that lenition, but it can be specified in the same manner as the other mutation, namely by word class.

1) Nouns

a) in the genitive plural of both genders:

seomraí na dteach ‘the rooms of the houses’
ceist na mban ‘the women’s question’

b) after the prepositions i and ar (very occasionally in fixed phrases, cf. go above)

i dtosach ‘in the beginning’
i dtús a bpósta ‘at the beginning of their marriage’

c) after the numerals seven to ten:

Deich dteampall ‘ten churches’
Caithfidh tú do sheacht ndícheall a dhéanamh leis.
(throw-FUT you your seven best-attempt a do-AM with-it)
‘You’ll have to do your very best.’

d) after plural possessive pronouns, this applies even if dhá intervenes:

ár n-imní ‘our worries’
bhur mbóthar ‘your-PL road’
barúil a dhá mban ‘their two wives’ opinion’

2) Adjectives

Adjectives are only nasalised if they occur in a nasalizing environment and precede the noun. The only adjectives which can precede are quantifiers and numerals:

teach na dtrí deartháracha ‘the house of the three brothers’
i ngach cás ‘in every case’
ag an gcéad fhaill ‘at the first opportunity’
but: ar son a dteanga dúchasaí  

Nasalisation is optional for the ordinals ceathrú ‘fourth’, cúigiú, ‘fifth’ and fichiú ‘twentieth’ after analytical preposition and article:

leis an gcúigiú / cúigiú iarracht ‘at the fifth attempt’

It is compulsory after an adjective which occurs after the cardinals seven to nine. In practice-this only arises with the following idiom (for an example with a noun, see above):

Ba sheacht bhfearr ise ná eisean.
(was seven better she-EMPH than he-EMPH)
‘She was far better than he was.’

3) Verbs

Verb forms are not subject to nasalisation in the indication of tense or mood (contrast lenition) but are when preceded by one of a series of elements which can qualify them.


a) mura ‘unless’ Mura bhfuil sé in ann.
RESERVATIVE ‘Unless he is able.’
b) ‘if’ Dá mbeadh sé in ann.
POSSIBILITY ‘If he were able.’

Temporal conjunction

a) sula ‘before’ Sula bhfaighidh sí ceann eile.
  PRECEDING IN TIME ‘Before she gets another one.’


a) an An mbíonn siad le fáil?
FORMATIVE ‘Are they (always) available?’
b) ‘where’ Cá mbíonn siad le fáil?
LOCATIVE ‘Where are they (always) available?’


a) a
RELATIVE+NOMINAL An chúairt a bhfuil súil aige leis.
He did everything he had time for.
INCLUSIVE PRONOUN Rinne sé a bhfuair sé am chuige.
‘The visit he’s looking forward to.’

b) go Bhí faitíos uirthi go dteipfidh sé.
RELATIVE+VERBAL She was afraid he would fail.

Introducing clauses of

1) TIME Fan go mbeidh sé níos fearr.
Wait until it is better.
2) CAUSALITY Beidh áthas orthu go bhfuil sibh ann.
They’ll be pleased that you’re there.
3) PURPOSE D’imigh sé go mbeadh an gnó curtha de.
He left in order to be rid of the matter.
4) POSSIBILITY Go mb’fhéidir é.
(in absolute form) It may be so.

Prefix D

1) the past indicative
2) the past habitual indicative
3) the conditional

Prefix-D consists of d’, /d/ placed before a verb which begins with a vowel or with f, /f/ which is reduced to Ø, fh before the prefixation. It is found in the three tenses given above.

D’éist sé go cúramach leis an gceist.
‘He listened carefully to the question.’
D’fhan sé chun an taoiseach nua a fheiceáil.
‘He stayed to see the new prime minister.’

Prefix-D is not found before the past autonomous:

Iarradh uirthi gan bheith déanach.
‘She was asked not to be late.’

In Munster Irish (southern Irish) prefix D is found frequently with verbs which begin in neither a vowel nor a lenited fh:

Do dhíol mé mo theach le gairid.
‘I sold my house a short time ago’.