Investigating the Learnability of a Rogue Grammar: Null Subject Parameter Resetting in Second Language Acquisitio

Access to Universal Grammar (UG) and the ability for parameter setting under Principles and Parameters Theory are proposed to explain how first and second language acquisition is possible given Poverty of the Stimulus (POS) effects. Following from this position is the claim that interlanguage grammars are constrained by UG and are never "rogue" (inconsistent with the principles and parameters of UG), but empirical results have been inconclusive. This research approaches the question of access to UG in SLA from a new angle by examining the learnability of a rogue grammar.;This study examines English L1's ability to learn artificial grammars with four different settings for the Null Subject Parameter (NSP): two that match the setting in English but have different verbal paradigms, one that matches the setting in Spanish, and one that is rogue (a setting not found in any natural languages). The four artificial grammars were constructed by the researcher: the rogue quality arises from a violation of the Morphological Uniformity Hypothesis, which is an implicational universal related to the NSP. Four groups of learners were taught a small portion of one of the four different artificial grammars using computer-based, covert instruction. Learners then completed a Vocabulary Test, a Conjugation Test, a Grammaticality Judgment Task to measure NSP resetting, and a Co-Reference Judgment Task to test knowledge of the Overt Pronoun Constraint, which is attested to exhibit POS effects. Response data to the nearest millisecond was collected.;Since access to UG is claimed to "fill in" the gaps of impoverished input, learning a rogue grammar from impoverished input should be harder than learning a natural grammar from impoverished input because UG cannot "fill in" the gaps for the rogue grammar like it can for the natural grammar. Results demonstrating that the rogue grammar is harder to learn (lower accuracy rates and/or longer reaction times) than the natural grammars could suggest access to UG in adult SLA.;The comparative learnability of the four grammars is analyzed based on accuracy and response times. Results indicate that the two grammars sharing English's setting for the NSP were the easiest to learn, demonstrating transfer. There is some indication that the rogue grammar was harder to learn than the grammar with a Spanish-like setting for the NSP, but this is a tentative claim that should be more fully examined through further refinement of this study.