Towards a Parameter Hierarchy for Alignment

This paper proposes a parameter hierarchy to derive all and only the various clausal alignments attested in natural languages (accusative, split-S, morphologically ergative, tripartite, syntactically ergative high and low absolutive). These alignments are derived from five dependent parameters which, it is argued, also serve to derive a number of otherwise mysterious universal implications, such as the ban on split-S syntactically ergative languages. Rather than being prespecified in Universal Grammar, it is proposed that the parameter hierarchy in question is structured by the pressure for convergence: ordering the relevant parameters in any other way makes possible non-convergent derivations. As such, the parameter hierarchy provides not only a characterisation of which alignments are attested in natural language but also the beginnings of an explanation as to why we find these alignments and no others.