Alternation

Topics: Phonology

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Alternation is the phenomenon where a morpheme presents various phonological realisations depending on its environment. Each one of these realisations is called an alternant.

An example of a morpheme that presents alternation is the English morpheme for the plural, -s/-es:

• When a sibilant or an affricate precedes it, it’s realised as /ɪz/ (e.g. masses is /masɪz/)
• When a voiceless consonant precedes it, it’s realised as /s/ (e.g. cats is /kats/)
• When a voiced consonant preceds it, it’s realised as /z/ (e.g. dogs is /dɒgz/)