Social robots have limited social competences. This leads us to view them as depictions of social agents rather than actual social agents. However, people also have limited social competences. We argue that all social interaction involves the depiction of social roles and that they originate in, and are defined by, their function in accounting for failures of social competence.

Despite enthusiastic agreement that experimental data are directly relevant for determining grammar architecture, we present one main objection to the conclusions that the authors draw from their results: The data are perfectly compatible – in fact, much more in line – with an alternative that does not rely on syntactic representations. Instead, it is processing actions whose activation for comprehension/production explains intra-/inter-speaker priming.

We argue that to reflect participant interactivity in conversational dialogue, the Christiansen & Chater (C&C) perspective needs a formal grammar framework capturing word-by-word incrementality, as in Dynamic Syntax, in which syntax is the incremental building of semantic representations reflecting real-time parsing dynamics. We demonstrate that, with such formulation, syntactic, semantic, and morpho-syntactic dependencies are all analysable as grounded in their potential for interaction.

This paper argues that, with syntax defined as progressive projection of semantic representations along the left-to-right dimension provided by the sequence of words (Cann, Kempson & Marten 2005), explanations for local and (multiple) nonlocal scrambling of NPs in Japanese and Korean follow from general principles of tree growth, allowing differences between the languages while nevertheless retaining an integrated account of scrambling itself. This formalism is similar to the parsing mechanism of Miyamoto (2002), but goes further in using this as the base grammar formalism, with all concepts of movement replaced by progressive articulation of structural underspecification and tree growth starting from the left periphery. The account extends the analysis of Japanese scrambling of Cann et al. to encompass multiple long-distance scrambling, capturing both the attendant relative locality restriction on the constituents moved, and interaction of this restriction with scope-construal effects. Scope-construal variability is expressible as interaction between individual lexical specifications for the two languages and general constraints on scope construal; and the relative locality constraint on the construal of the expressions involved in multiple long-distance scrambling is an immediate consequence of the general dynamics of the framework. The resulting account extends Hawkins' (2004) program of defining grammars relative to performance considerations.

This paper argues that pragmatic processes and syntactic constraints interact, that we can nevertheless retain the assumption that the natural language faculty is fully encapsulated, and that the problems posed by the phenomenon of gapping (bare argument ellipsis) can be resolved by analysing gapping as an instance of such interaction. A new model of language is sketched out, a model which is a formal reconstruction of assumptions about the language faculty and its relation to central cognitive processes made by Fodor. and Sperber and Wilson. A fragment is defined to cover pronominal anaphoric dependency and quantifier binding, and a new analysis of bare argument ellipsis (gapping) is presented.

This commentary argues that dialogue alignment can be explained if parsing-directed grammar formalisms are adopted. With syntax defined as monotonic growth of semantic representations as each word is parsed, alignment between interlocutors is shown to be expected. Hence, grammars can be evaluated according to relative success in characterizing dialogue phenomena.

This paper informally outlines a Labelled Deductive System for on-line language processing. Interpretation of a string is modelled as a composite lexically driven process of type deduction over labelled premises forming locally discrete databases, with rules of database inference then dictating their mode of combination. The particular LDS methodology is illustrated by a unified account of the interaction of wh-dependency and anaphora resolution, the so-called ‘cross-over’ phenomenon, currently acknowledged to resist a unified explanation. The shift of perspective this analysis requires is that interpretation is defined as a proof structure for labelled deduction, and assignment of such structure to a string is a dynamic left-right process in which linearity considerations are ineliminable.

Over the course of the last twenty-five years, linguistic theory has established itself as providing one of the major routes towards an understanding of the human mind. With increasing precision we have been able to address the problem of articulating in detail the structured capacities the human mind brings to the problem of language acquisition. Along the way there have been doubters, much of the doubt having arisen because of the apparently unbridgeable gap the theory demands between the language user's capacity and the interaction of this capacity with more general cognitive skills. Such doubters as there were received little reassurance from looking at work on performance or language use, for there has been little more than speculative philosophy on the one hand (most notably by Paul Grice, 1975) and articulation of detailed processing mechanisms on the other (e.g. Fodor, 1978; Frazier, 1979; Frazier & Fodor, 1978), without any overall theory. J. A. Fodor (1982, 1983) has led the field in cognitive psychology with his representational theory of mind. But we have till now had no theory of the central cognitive mechanism. Relevance Theory (Sperber & Wilson, 1986) provides us with a contender. It makes specific claims about the central cognitive mechanism and about the relation of natural language to that central mechanism. Against this framework, we are at last able to formulate precise proposals about the grammar-cognition interface, and in so doing provide answers to the psychological reality questions which have gone unanswered for so long: What is the relation of grammars to utterance–interpretation? What is the nature of the link between grammars and the central cognitive mechanism? What is the relation between a speaker's knowledge of his language and his general knowledge?