Allomorph - Stem Allomorphy

Stem Allomorphy

Allomorphy can also exist in stems or roots, as in Classical Sanskrit:

There are three allomorphs of the stem: /vaːk/, /vaːt͡ʃ/ and /vaːɡ/. The allomorphs are conditioned by the particular case-marking suffixes.

The form of the stem /vaːk/, found in the nominative singular and locative plural, is the etymological form of the morpheme. Pre-Indic palatalization of velars resulted in the variant form /vaːt͡ʃ/, which was initially phonologically conditioned. This conditioning can still be seen in the Locative Singular form, where the /t͡ʃ/ is followed by the high front vowel /i/.

But subsequent merging of /e/ and /o/ into /a/ made the alternation unpredictable on phonetic grounds in the Genitive case (both Singular and Plural), as well as the Nominative Plural and Instrumental Singular. Hence, this allomorphy was no longer directly relatable to phonological processes.

Phonological conditioning also accounts for the /vaːɡ/ form found in the Instrumental Plural, where the /ɡ/ assimilates in voicing to the following /bʱ/.