Task-Specific Artifacts of Parametric Properties in English as a Second Language Acquired by Persian-Speaking Learners

This experimental study investigated the learners’ integrative acquisition of obligatory overt subjects and subject-verb clause agreement in English as an L2. In L1 acquisition research, correlations between superficially unrelated linguistic phenomena are analyzed in terms of integrative effects. For instance, in English L1 acquisition, there is evidence for an integrative appearance of subject-verb clause agreement and the decrease of incorrect null subjects. The developmental connection between these two specifications in L1 acquisition has been interpreted as setting the syntactic properties of the same cluster. Vainikka and Young-Scholten (1994, 2013) have claimed that the acquisition of subject-verb agreement and non-pro-drop in adult L2 learners developmentally coincide in the same way as it does in child L1 learners. This is taken to indicate that UG parameters are fully accessible to adult L2 learners. Thus, the present research reported on Reaction-Time (RT) experiments investigating subject-verb clause agreement and obligatory subjects in 30 Persian learners of English in three proficiency levels, each level consisting of five early starters and five late starters. Our main finding was that the two phenomena do not covary in the Persian learners of English as L2 indicating that specifications of subject-verb clause agreement and obligatory subjects are acquired separately from one another, rather than through integrative resetting. Finally, it is suggested that L2 learners should be explicitly exposed to all parametric features and individual evidence of a syntactic cluster in the second language context.