A proposal that syntax extends to the domain of discourse in making core syntax link to the conversational context.
In Syntax in the Treetops, Shigeru Miyagawa proposes that syntax extends into the domain of discourse by making linkages between core syntax and the conversational participants. Miyagawa draws on evidence for this extended syntactic structure from a wide variety of languages, including Basque, Japanese, Italian, Magahi, Newari, Romanian, and Spanish, as well as the language of children with autism. His proposal for what happens at the highest level of the tree structure used by linguists to represent the hierarchical relationships within sentences—“in the treetops”—offers a unique contribution to the new area of study sometimes known as “syntacticization of discourse.”
Miyagawa's main point is that syntax provides the basic framework that makes possible the performance of a speech act and the conveyance of meaning; although the role that syntax plays for speech acts is modest, it is critical. He proposes that the speaker-addressee layer and the Commitment Phrase (the speaker's commitment to the addressee of the truthfulness of the proposition) occur together in the syntactic treetops. In each succeeding chapter, Miyagawa examines the working of each layer of the tree and how they interact.
“Shigeru Miyagawa's monograph amounts to a resurrection of one of the boldest, yet most criticized, proposals in syntax, the 'performative hypothesis' by Ross (1970), Davison (1973), and Sadock (1974). Drawing on his own research and the research of many other scholars investigating a wide range of languages, Miyagawa presents a full and innovative picture of syntax beyond those structures that are concerned with formulating mere truth conditions, and relate to the actual use of language in communication. As stated in a popular textbook on pragmatics in 1983, 'the performative hypothesis cannot be dismissed as being of historical interest only, as publications still appear in which it is assumed to be true.' In fact, it is very much alive fifty years after it was first conceived.”
Manfred Krifka, Leibniz-Zentrum Allgemeine Sprachwissenschaft (ZAS) and Humboldt Universität Berlin