Base modification is a non-concatenative process described as a systematic change to the sound structure of a word’s base. Base modification can include lengthening, shortening, tonal changes, vowel changes, etc..
- Suttles (2003) describes a vowel mutation process (also known as umlaut), where the stem of a word containing /e/ shifts to /á/ with the addition of certain suffixes (p. 20). Since this is changing the base through a vowel mutation, this can be referred to as base modification, and is therefore a non-concatenative morphological process.
- The examples below illustrate that when the /-θət/ suffix ‘onself’ is added to a base, the base vowel changes. This can be observed as follows:
- The base /t́éʔt-/ ‘test him, try out’ becomes /t́áʔθət/ (the vowel of interest is bolded in order to demonstrate this).