Determining argument structure in sign languages
In this paper we offer an overview of existing analyses of argument structure that sets the stage for further inquiry into this domain. The particular structure of the lexicon in sign languages (SLs) is introduced, with special attention to the agreement patterns found in lexical predicates, as overt agreement marking in the set of verbs that can realize it offers a window into verb meaning and overt argument realization. Classifier predicates, on the other hand, have proven to be a very rich domain for research on argument structure: unaccusative/unergative and unaccusative/transitive alternations have been identified in American Sign Language (ASL) classifier constructions, and replicated in other SLs. As expected, the validity of valency tests is sometimes limited to one language, but the alternations are attested crosslinguistically and can be applied to lexical verbs as well. Specially interesting is the traditional divide between agreement marking in lexical predicates and spatial agreement marking in classifier constructions, often seen as having a different nature. Given the fact that the morphological exponence of agreement is superficially the same (i.e. the path or trajectory that the verbal sign crosses in signing space), the divide must be motivated on empirical arguments, which are not always compatible or consistent with a broad empirical coverage. We identify a number of areas where research should be carried out in order to advance our ounderstanding of argument structure in languages in the visual-gestural modality, in order to determine which of the observed properties is really modality-specific.