Experimental syntax and the variation of island effects in English and Italian

The goal of this article is to explore the utility of experimental syntax techniques in the investigation of syntactic variation. To that end, we applied the factorial definition of island effects made available by experimental syntax (e.g., Sprouse et al. 2012) to four island types (wh/whether, complex NP, subject, and adjunct), two dependency types (wh-interrogative clause dependencies and relative clause dependencies) and two languages (English and Italian). The results of 8 primary experiments suggest that there is indeed variation across dependency types, suggesting that wh-interrogative clause dependencies and relative clause dependencies cannot be identical at every level of analysis; however, the pattern of variation observed in these experiments is not exactly the pattern of variation previously reported in the literature (e.g., Rizzi 1982). We review six major syntactic approaches to the analysis of island effects (Subjacency, CED, Barriers, Relativized Minimality, Structure-building, and Phases) and discuss the implications of these results for these analyses. We also present 4 supplemental experiments testing complex wh-phrases (also called D-linked or lexically restricted wh-phrases) for all four island types using the factorial design in order to tease apart the contribution of dependency type from featural specification. The results of the supplemental experiments confirm that dependency type is the major source of variation, not featural specification, while providing a concrete quantification of what exactly the effect of complex wh-phrases on island effects is.