Alternation (linguistics)

In linguistics, an alternation is the phenomenon of a morpheme exhibiting variation in its phonological realization. Each of the various realizations is called an alternant. The variation may be conditioned by the phonological, morphological, and/or syntactic environment in which the morpheme finds itself.

Alternations provide linguists with data that allow them to determine the allophones and allomorphs of a language's phonemes and morphemes and to develop analyses determining the distribution of those allophones and allomorphs.

The term "sound change" refers to diachronic changes, which occur in a language's sound system. On the other hand, "alternation" refers to changes that happen synchronically (within the language of an individual speaker, depending on the neighbouring sounds) and do not change the language's underlying system.

Phonologically conditioned alternation

An example of a phonologically conditioned alternation is the English plural marker commonly spelled s or es.<ref>Template:Cite book </ref> This morpheme is pronounced Template:IPA, Template:IPA, or Template:IPA,<ref group=note>The vowel of the inflectional suffix -Template:Angbr may belong to the phoneme of either Template:IPA or Template:IPA depending on dialect, and Template:Angbr IPA is a shorthand for "either Template:IPA or Template:IPA". This usage of the symbol is borrowed from the Oxford English Dictionary.</ref> depending on the nature of the preceding sound.

1. If the preceding sound is a sibilant consonant (one of Template:IPA), or an affricate (one of Template:IPA), the plural marker takes the form Template:IPA. Examples:
   • mass Template:IPA, plural masses Template:IPA
   • fez Template:IPA, plural fezzes Template:IPA
   • mesh Template:IPA, plural meshes Template:IPA
   • mirage Template:IPA, plural mirages Template:IPA
   • church Template:IPA, plural churches Template:IPA
   • bridge Template:IPA, plural bridges Template:IPA
2. Otherwise, if the preceding sound is voiceless, the plural marker takes the likewise voiceless form Template:IPA. Examples:
   • mop Template:IPA, plural mops Template:IPA
   • mat Template:IPA, plural mats Template:IPA
   • pack Template:IPA, plural packs Template:IPA
   • cough Template:IPA, plural coughs Template:IPA
   • myth Template:IPA, plural myths Template:IPA
3. Otherwise, the preceding sound is voiced, and the plural marker takes the likewise voiced form Template:IPA.
   • dog Template:IPA, plural dogs Template:IPA
   • glove Template:IPA, plural gloves Template:IPA
   • ram Template:IPA, plural rams Template:IPA
   • doll Template:IPA, plural dolls Template:IPA
   • toe Template:IPA, plural toes Template:IPA

Alternation related to meaning

Morphologically conditioned alternation

French has an example of morphologically conditioned alternation. The feminine form of many adjectives ends in a consonant sound that is missing in the masculine form. In spelling, the feminine ends in a silent e, while the masculine ends in a silent consonant letter:<ref>Template:Cite book</ref>

• masculine Template:Lang Template:IPA, feminine Template:Lang Template:IPA Template:Gloss
• masculine Template:Lang Template:IPA, feminine Template:Lang Template:IPA Template:Gloss
• masculine Template:Lang Template:IPA, feminine Template:Lang Template:IPA Template:Gloss
• masculine Template:Lang Template:IPA, feminine Template:Lang Template:IPA Template:Gloss
• masculine Template:Lang Template:IPA, feminine Template:Lang Template:IPA Template:Gloss
• masculine Template:Lang Template:IPA, feminine Template:Lang Template:IPA Template:Gloss

Syntactically conditioned alternation

Syntactically conditioned alternations can be found in the Insular Celtic languages, where words undergo various initial consonant mutations depending on their syntactic position.<ref>Template:Cite journal</ref> For example, in Irish, an adjective undergoes lenition after a feminine singular noun:

• unmutated Template:Lang Template:IPA Template:Gloss, mutated in Template:Lang Template:IPA Template:Gloss

In Welsh, a noun undergoes soft mutation when it is the direct object of a finite verb:

• unmutated Template:Lang Template:IPA "bike", mutated in Template:Lang Template:IPA Template:Gloss

See also

• Phonological rule
• Sound change
• Apophony
• Sandhi
• Allophone