How redundant is language really? Agent-recipient disambiguation across time and space

Redundant marking of grammatical relations seems to be commonplace across languages, and has been shown to benefit learning as well as robust information transmission. At the same time, languages also exhibit trade-offs between strategies such as case marking or word order, suggesting that redundancy may also be dis-preferred in line with a tendency towards communicative efficiency. In the present paper, we assess redundancy  in terms of number of strategies used simultaneously to mark specific relations within individual utterances (syntagmatic redundancy) in light of these competing motivations. Our test case is participant role disambiguation in English and Dutch, specifically the interaction of constituent order, case, prepositional marking, and agreement to distinguish agents and recipients in ditransitive clauses. Using evidence from corpora of Present Day Dutch and English as well as data from Middle English, we find that redundancy is prevalent, albeit within certain limits.