An allomorph is one of two or more complementary morphs which manifest a morpheme in its different phonological or morphological environments.
The allomorphs of a morpheme are derived from phonological rules and any morphophonemic rules that may apply to that morpheme.
(English)
The plural morpheme in English, usually written as '-s', has at least three allomorphs:
This page is an extract from the LinguaLinks Library. Version 5.0 published on CD-ROM by SIL International, 2003.