Stratal Phonology differentiates between stored nonanalytical forms (stem-level) and active analytical processes (word-level) in word-formation, which has implications for language with nonconcatenative morphology. In the context of Hul'q'umi'num' (Salish), this differentiates between a stored imperfective stem and an analytical process of creating a plural form. This also makes predictions about learner errors and where variation might be observed. For example, in places where speakers do not have a stored imperfective stem, phonological regularity may prevail, reflecting the application of the stem-level grammar in the absence of a stored stem. This raises questions about learnability and whether all reduplicative processes should be taught the same way. For example, it may be useful to have L2 learners of Hul'q'umi'num' memorize imperfective stems while learning more abstract rules to form plurals.