Generalizations on variations in comprehension and production: a further source of variation and a possible account.

Many types of variation can be found in agrammatic aphasia. Drai and Grodzinsky (in press) presented a convincing account for variations between syntactic structures, between individuals and across languages. However, there is one source of variation that is not accounted for by their approach: the variation that exists within individuals with agrammatism between different structures that are derived by movement. Such variation can be found in comprehension mainly between passive sentences and object relative clauses.