ABSTRACT
This chapter examines how and if three different frameworks – Obata, Epstein, and Baptista (2015), Obata and Epstein (2016), Chomsky (2015, 2020), and Epstein, Kitahara, and Seely (2016) – are able to account for language variation as illustrated by Kilega agreement phenomena, English Tough-Constructions, Kisongo Maasai (D-to-C movement) and English (T-to-C movement). A central question is this: “If UG and 3rd factor are invariant, how can I-language variation, i.e. linguistic variation, possibly be explained, without appeal to language specific, linguistic parameters, within UG?” This paper argues that variation occurs in the order of rule application in the narrow syntax (contra Berwick and Chomsky’s restriction of all variation to the PF component) because 3rd factor leaves certain orders unspecified, allowing more than one optimal type, hence allowing variation in I-languages. Children acquire the ordering specific to their native language based on environmental input (externalized linguistic acoustic disturbances, or manual gestures for sign, which, when input into UG and 3rd factor, determine a specific rule ordering or orderings).
