Syntactic breakdown and recovery of clausal structure in agrammatism

We studied the recovery of clause structures in four agrammatic patients by performing a longitudinal analysis of their spontaneous production. We classified their utterances in terms of legitimacy of the syntactic structure and rate of subordination. The results show that, initially, patients omit verbs, avoid subordination, just employ present tense, and substitute finite verbs with infinitives. During the recovery they start employing other tenses and subordinate clauses and reduce the use of infinitives. Data suggest a mixed syntactic and morphological origin of the impairment. Assuming that phrasal representations are built bottom-up from an array of lexical items, we propose that syntactic structures recover stepwise, with the lower portion of the syntactic tree becoming accessible before higher portions. We claim that, despite superficial similarities between agrammatic and children's speech, e.g., use of infinitives instead of finite verbs, a unified account is not viable.