The present experiment sought evidence of the involvement of derivational word morphology in speech production processes. A version of the word order competition technique (Baars & Motley, 1976) was used to induce a special kind of verbal slip, namely stranding exchange errors. In these errors, word fragments belonging to two words exchange by stranding their remaining fragments. The linguistic material was selected so that it could be determined whether morphemic stranding exchanges had a higher probability of occurring than non-morphemic ones under conditions in which various phonological and structural properties of the target words were controlled. The distribution of slips obtained clearly points to the implication of word derivational morphology in speech production processes.
Pillon, A. (1998). Morpheme units in speech production: Evidence from laboratory-induced verbal slips. Language and Cognitive Processes, 13(4), 465-498. https://doi.org/10.1080/016909698386465 (Original work published 1998)