Inlinguistics, analternation is the phenomenon of amorpheme exhibiting variation in itsphonological realization. Each of the various realizations is called analternant. The variation may be conditioned by the phonological,morphological, and/orsyntactic environment in which the morpheme finds itself.
Alternations provide linguists with data that allow them to determine theallophones andallomorphs of a language's phonemes and morphemes and to develop analyses determining the distribution of those allophones and allomorphs.
The term "sound change" refers todiachronic changes, which occur in a language's sound system. On the other hand, "alternation" refers to changes that happensynchronically (within the language of an individual speaker, depending on the neighbouring sounds) and do not change the language'sunderlying system.
An example of a phonologically conditioned alternation is theEnglishplural marker commonly spelleds ores.[1] This morpheme is pronounced/s/,/z/, or/ᵻz/,[note 1] depending on the nature of the preceding sound.
If the preceding sound is asibilant consonant (one of/s/,/z/,/ʃ/,/ʒ/), or anaffricate (one of/tʃ/,/dʒ/), the plural marker takes the form/ᵻz/. Examples:
mass/ˈmæs/, pluralmasses/ˈmæsᵻz/
fez/ˈfɛz/, pluralfezzes/ˈfɛzᵻz/
mesh/ˈmɛʃ/, pluralmeshes/ˈmɛʃᵻz/
mirage/mɪˈrɑːʒ/, pluralmirages/mɪˈrɑːʒᵻz/
church/ˈtʃɜːrtʃ/, pluralchurches/ˈtʃɜːrtʃᵻz/
bridge/ˈbrɪdʒ/, pluralbridges/ˈbrɪdʒᵻz/
Otherwise, if the preceding sound isvoiceless, the plural marker takes the likewise voiceless form/s/. Examples:
mop/ˈmɒp/, pluralmops/ˈmɒps/
mat/ˈmæt/, pluralmats/ˈmæts/
pack/ˈpæk/, pluralpacks/ˈpæks/
cough/ˈkɒf/, pluralcoughs/ˈkɒfs/
myth/ˈmɪθ/, pluralmyths/ˈmɪθs/
Otherwise, the preceding sound is voiced, and the plural marker takes the likewise voiced form/z/.
French has an example of morphologically conditioned alternation. Thefeminine form of manyadjectives ends in aconsonant sound that is missing in the masculine form. In spelling, the feminine ends in asilent e, while the masculine ends in a silent consonant letter:[2]
Syntactically conditioned alternations can be found in theInsular Celtic languages, where words undergo various initialconsonant mutations depending on their syntactic position.[3] For example, inIrish, an adjective undergoeslenition after a feminine singular noun:
unmutatedmór[mˠoːɾˠ]'big', mutated inbean mhór[bʲanwoːɾˠ]'a big woman'
^The vowel of the inflectional suffix -⟨es⟩ may belong to the phoneme of either/ɪ/ or/ə/ depending on dialect, and ⟨ᵻ⟩ is a shorthand for "either/ɪ/ or/ə/". This usage of the symbol is borrowed from theOxford English Dictionary.
