Topics: Phonology

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/)