This paper examines the role of L1 transfer in second language acquisition process. It aims to investigate if adult Turkish L2 learners of English make use of their L1 parameter values while dealing with the target subject-matter in L2 or not. It specifically focuses on four island constraints (Wh-island Constraint, Complex NP Island Constraint, Adjunct Island Constraint and Sentential Subject Constraint) in the target language. The data were collected through a grammaticality judgment test and a wh-question formation test from two learner groups (advanced, N:66; intermediate, N: 68) and a control group (N:58). The results of the study showed that the participants make use of the parameter values of the target language rather than leaning on the ones that their native language possesses. Their performance on the target subject-matter was rather similar that of the control group members. The argument & adjunct asymmetry that exists in their mother tongue was not observed in their L2 productions. These results show that their second language acquisition process is constrained directly by UG rather than indirectly through L1.
Second language acquisition, Universal Grammar, Mother tongue influence, Turkish, English