In Prunet, Béland, and Idrissi 2000, we presented evidence from an aphasic subject that argued for the morphemic status of Arabic consonantal roots. We predicted that inaudible glides in weak roots should resurface in metathesis and template selection errors, but at the time the relevant data were unattested. Here, we present such data, obtained from a new series of experiments with the same aphasic subject. Arabic hypocoristic formation offers another case of glide resurfacing. Both sources of data confirm that Arabic consonantal roots are abstract morphemic units rather than surface phonetic units.

This article is concerned with external evidence bearing on the nature of the units stored in the mental lexicons of speakers of Semitic languages. On the basis of aphasic metathesis errors we collected in a single case study, we suggest that roots can be accessed as independent morphological units. We review documented language games and slips of the tongue that lead to the same conclusion. We also discuss evidence for the morphemic status of templates from aphasic errors, language games, and slips of the tongue. We conclude that the available external evidence is best accounted for within a morpheme-based theory of morphology that forms words by combining roots and templates.