Sign order and argument structure in a Peruvian home sign system

Home sign systems are gestural communication systems that arise when a deaf child is deprived of manual communication, but not social interaction. Yet, despite not having conventional linguistic input, the sign systems developed by such children have been found to exhibit many properties of natural language. In this paper, I examine the productions of RCM, a 28-year-old deaf home signer, and his three most common interlocutors, all living in Nueva Vida, a village in Peruvian Amazonia. According to his parents, RCM has never spoken and has used gestural communication since childhood. Neither RCM nor anyone within the community have been exposed to a conventional sign language. However, RCM's family and friends gesture with him to communicate. Analysis focused on the use of spatial modulation and sign order in argument structure and negation for all four signers, comparing consistency both internal to the signer and across signers. I found that RCM produces a consistent sign order for transitive constructions, intransitive constructions and negation. RCM used sign order to mark semantic role contrasts. He produced two different lexical negation signs to mark three types of grammatical negation. The ordering of semantic arguments and negation was matched in almost all cases by the three hearing interlocutors. Although RCM had a consistent and productive means of assigning arguments, he also employed space in a class of signs that can be classified as `directional verbs'. These action signs marked the patient or recipient through movement. In addition to spatial modulation, he assigned referents to abstract space and was able to refer back to these referents using points or spatial modulation. All three hearing signers were found to use some degree of spatial modulation. However, the degree to which the hearing signers were capable of using abstract space varied across signers. I showed that RCM is the innovator of these structures and that the hearing signers learned the structures from RCM.