Specific Language Impairment (SLI) has been defined as a non-acquired language disorder with language difficulties in the absence of hearing acuity impairment, mental retardation, motor-articulator impairment, frank neurological impairment, or psycho-emotional disturbance (on criteria setting, cf. Stark & Tallal, 1981). Research findings indicate that grammatical errors are a “hallmark” of SLI (Bishop, 1994). In particular, inflectional and derivational morphology is severely impaired in SLI (Clahsen, 1989, 1991; Gopinik & Crago, 1991; Gopnik & Goad, 1997; Rice, Wexler & Cleave, 1995). The impairment also extends to syntactically complex utterances involving embedded structures as shown by production and comprehension data (van der Lely, 1998). Based on empirical data, diverse explanatory models of SLI have been developed in an attempt to identify the status of the linguistic mechanism attributed to SLI children, the locus of the deficit as well as the linguistic outcome of the deficit (Rice, 1994).