The derivation of postverbal subjects: Evidence from agrammatic aphasia

The study reported in this paper appeals to data from agrammatic aphasia to confront two competing analyses of the derivation of postverbal subjects in languages which permit free inversion. In one of the analyses, postverbal subjects are derived by movement, while in the other, they are base-generated in situ. According to a prominent hypothesis which attempts to explain the pattern of sparing and loss in agrammatism in terms of current linguistic theory, the only syntactic deficit is the loss of trace. This movement-derived 'trace-deletion' hypothesis has been successful in predicting what agrammatics can and cannot comprehend. In the present study, these predictions are first of all confirmed for Spanish-speaking agrammatics on a range of structures for which predictions are identical under both movement and non-movement analyses. These structures serve as a control, establishing that the claims of the trace-deletion hypothesis are valid. They pave the way for the critical test of the VS passive, the only structure for which the competing analyses yield different predictions. Agrammatic data on the VS passive are used to adjudicate between the competing analyses. Since agrammatic subjects perform randomly on VS passives, it is concluded that the postverbal subject is derived by movement.