Andreas Trotzke - Syntactic Complexity across Interfaces

recursion is the defining property of natural language (Hauser et al. 2002). In the light of more recent claims according to which complex syntax is not a universal property of all living languages (Everett 2005), the issue of how to detect and define syntactic complexity has been revived with a combination of classical and new arguments (Nevins et al. 2009).

The existing collections on the nature of syntactic complexity either deal with syntactic complexity from a functional-typological perspective (Miestamo et al. 2008; Sampson et al. 2009) or place a premium on the property of syntactic recursion (van der Hulst 2010; Sauerland and Trotzke 2011; Roeper and Speas 2014). In contrast, the current volume makes a new contribution to the ongoing debate by taking into account the recent development in linguistic theory to approach UG from below by referring to both grammar-internal and grammar-external interfaces when explaining design features of the human language faculty (Chomsky 2007). According to this shift in perspective, it is reasonable to assume that UG only contains properties such as recursive Merge, binary branching structure, and the valued-unvalued feature distinction. All other properties of grammar might follow from the interaction between UG and other components within the model of grammar (the phonological and the semantic component; i.e. grammar-internal components) and from the interplay between UG and grammar-external components such as the performance and acquisition systems. As for the interaction with grammar-internal components, the new division of labor among the components of the model of grammar raises new issues for defining and detecting syntactic complexity. In particular, the question of the complexity of grammar has to be answered separately for narrow syntax and for the grammar as a whole, including the interface components (Trotzke and Zwart 2014). As for the interaction with grammar-external components, Trotzke et al. (2013) show that systematic properties of performance systems (the performance interface, according to their terminology) can play an important role within the research program outlined by Chomsky (2005, 2007). In particular, investigations of the performance interface can revise current conceptions of UG by relegating widely assumed grammatical constraints to properties of the performance systems, as recently argued, for instance, by Bever (2009) for the Extended Projection Principle or by Hawkins (2013) for the Final-Over-Final Constraint (Biberauer et al. 2014).

Given this conceptual background of approaching the issue of syntactic complexity from the perspective of recent linguistic theory, the volume starts with two contributions that deal with the formal complexity of natural languages in terms of the Chomsky hierarchy, the most prominent complexity measure in formal language theory. These two contributions set the scene for the volume by discussing general aspects of grammar architecture and by turning to the question of whether languages can vary as to their formal complexity. The two papers are followed by three contributions that address specific issues of clausal embedding (small clauses, parentheses, peripheral adverbial clauses, and right dislocation/afterthought constructions). The last part of the volume contains three papers that provide accounts of how to address topics revolving around syntactic complexity in terms of grammar-external interfaces in the domain of language acquisition.