Unlike productive morphology, unproductive morphological processes are those that are not commonly found in the language. Unproductive morphological processes are not formalized as rules in the language as a result of being less common.
- Secwepemctsín: Gibson (1973) describes an unproductive morphological process in Secwepemctsín as being compounding in order to create stems (p. 38). Only one root is found with an incorporated stem, /pł/ ‘to possess.’
- The following example illustrates an uncommon process of compounding which combines the /pł/ root + stem.