Initial Consonant Mutations
For a definition of the basic notion see Initial Consonant Mutation (definition)
Morphological and Syntactic Triggering
Explanation of "Triggers" and "Targets"
Although these mutations surface as phonological changes, the historical (diachronic) sources of these changes are should not be considered caused by the phonological system of the current (synchronic) language (Stewart 2013, Green 2007, Pyatt 1997, Rogers 1972, Leiber 1983).
Initial consonant mutations are the changes of a "target" caused by a "trigger." For example, a very common type of initial consonant mutation is the lenition of feminine adjectives which follow a singular feminine noun. In this case, the "target" is the adjective toilichte 'happy', and the trigger is the noun nighean, which has the inherent properties of feminine gender and singular number. Because it is a fact of Gaelic grammar that feminine singular nouns cause lenition of the following adjectives which describes them, the initial consonant of the adjectives toilichte becomes thoilichte (example 1a). This contrasts with the example in 1b, where gille 'boy' does not trigger a consonant mutation on the same following adjective, because it is masculine singular, not feminine.
nighean thoilichte girl happy "a happy girl"
gille toilichte boy happy "a happy boy"
Triggers in the language, exemplified by the feminine singular noun nighean above, tend to be syntactic or morphological, i.e. they encode grammatical information of the language. Triggers are always associated with a target, as presented in the (non-exhaustive) figure below. Further examples of triggers and targets may be found on the Lenition page.
|feminine singular noun||following adjective||caora mhòr||a big sheep|
|definite article||feminine singular nouns starting with b, c, g, m, p, f||a' chaora||the sheep|
|regular past tense||imperative form of the verb||phòg||kissed|
|preposition||definite noun||air a' bhàta||on the boat|
|certain possessive pronouns||possessed noun||a chòta||his coat|
|the numerals 1 and 2||following noun||dhà chu||two dogs|
The consonant mutations tend to be marked orthographically in written Gaelic. For example, lenition is represented with an orthographic <h> following the lenited consonant, except for <l>, <n>, <r>. In (1a) above, the [t] of toilichte becomes [h] in thoilichte. A full description of the phonetic changes of the lenited forms may be found on the Lenition page. A full description of the eclipsis mutation may be found on the Eclipsis page.
Irregularity of Triggers and Targets
While there are generalizations to be made about the occurrence of consonant mutation based off of the trigger and the target, there are, of course, exceptions. In Gaelic, though /t/ and /d/ regularly lenite to [h] and [j] or[γ] respectively, the noun taigh 'house' does not follow this rule.
//see also the main article lenition//
Lenition is an initial consonant mutation which "weakens" (cf. Latin lenis 'weak') the sound of the consonant at the beginning of a word. It is used to mark certain morphological contrasts and to mark inflection. Lenition is often marked orthographically by an <h> following the consonant which undergoes lenition.
For example, the 1st person singular possessive pronoun mo "my", causes lenition on the noun which follows it. The noun peann "pen" begins with a "p", but when it is lenited, it is written as pheann and the pronunciation changes (per the information given on the lenition page.)
peann pen "pen"
mo pheann 1.S.POSS pen "my pen"
//see also the main article Eclipsis//
Eclipsis is a morphophonological change triggered by certain function words (such as ar "our"). In words beginning with a vowel, this involves prefixing an orthographic <n-> in front of the word (e.g. ar n-athair, "our father").
athair father "father"
ar n-athair 1.PL.POSS father "our father"
Green, Antony D. 2007. Phonology limited (Linguistics in Potsdam 27). Potsdam, Universitätsverlag Potsdam.
Lieber, Rochelle. 1983. New developments in autosegmental morphology: Consonant mutation. WCCFL 2: 165-175.
Pyatt, Elizabeth J. 1997. An integrated model of the syntax and phonology of Celtic mutation. Harvard University dissertation.
Rogers, Henry. 1972. The initial mutations in modern Scots Gaelic. Studia Celtica 7: 63-85.
Stewart, Thomas W. 2013. The sub-types of initial lenition in Scottish Gaelic. In Cruichshank, Janet and Robert McColl Millar (eds.) 2013. After the Storm: Papers fro the Forum for Research on the Languages of Scotland and Ulster triennial meeting, Aberdeen 2012. Aberdeen: Forum for Research on the Languages of Scotland and Ireland, 100-116.