Morpheme
Allomorphs

Allomorphs are variants of a morpheme that differ in form but are semantically similar. For example, the English plural marker has three allomorphs: /-z/ (bug s), /-s/ (bat s), or /-ɪz, -əz/ (bus es). An allomorph is a concrete realization of a morpheme, which is an abstract unit. That is parallel to the relation of an allophone and a phoneme.
language:response_language[Polish]