An expectation-based account of subject islands and parasitism
Subject phrases are traditionally seen as syntactic environments that impose particularly strong constraints on extraction. Most research assumes a syntactic account (e.g. Kayne (1983); Chomsky (1986); Rizzi (1990); Lasnik and Saito (1992); Takahashi (1994); Uriagereka (1999), to mention only a few), but there are also pragmatic accounts (Erteschik-Shir and Lappin, 1979; Van Valin, 1986, 1995; Erteschik-Shir, 2006, 2007) as well as performance based approaches (Kluender, 2004). In this work I argue that none of these accounts captures the full range of empirical facts, and show that subject and adjunct phrases (phrasal or clausal, finite or otherwise) are by no means impermeable to non-parasitic extraction of nominal, prepositional and adverbial phrases. Moreover, the present reassessment indicates that the phenomena involving subject and adjunct islands defies the formulation of a grammatical generalization. Drawing from Engdahl (1983) and Kluender (2004), I argue that subject island effects have a functional explanation, independently motivated by pragmatic and processing limitations which conspire to create a narrow acceptability bottleneck. In my account, such processing limitations cause subject-internal gaps in languages like English to be heavily dispreferred and therefore extremely infrequent. In turn, this has led to heuristic parsing expectations that preempt subject-internal gaps and therefore speed up processing by pruning the search space of filler-gap dependencies. Such expectations cause processing problems when violated, unless they are dampened by prosodic and pragmatic cues that boost the construction of the correct parse. This account predicts subject islands and their (non-)parasitic exceptions.