The representation of inflectional morphology: evidence from Broca's aphasia

Dualistic models of inflection assume a qualitative distinction between affix-based regular forms and stored irregular forms, predicting that the two distinct mechanisms can be selectively affected in language disorders. We present data on German participle formation from 11 agrammatic Broca's aphasics which show that irregular participles can be selectively affected in agrammatism. Moreover, the distribution of errors reveals a frequency effect for irregular but not for regular participles. Both findings argue for a dualistic representation of inflection. Moreover, we want to propose a modification of dualistic models by suggesting that both regularity and irregularity are better conceived of as scalar.