Allomorph

For example, an English past tense morpheme is -ed, which occurs in several allomorphs depending on its phonological environment by assimilating the voicing of the previous segment or the insertion of a schwa after an alveolar stop.

The specific pronunciation that a plural morpheme takes on is determined by a set of morphological rules such as the following:[2] In English, the negative prefix in- has three allomorphs: [ɪn-], [ɪŋ-], and [ɪm-].

The phonetic form that the negative morpheme /ɪn-/ uses is determined by a set of morphological rules; for example:[3] The Sami languages have a trochaic pattern of alternating stressed and unstressed syllables.

Pre-Indic palatalization of velars resulted in the variant form /vaːt͡ʃ/, which was initially phonologically conditioned.

Phonological conditioning also accounts for the /vaːɡ/ form in the instrumental plural, in which the /ɡ/ assimilates in voicing to the following /bʱ/.