The second language acquisition (SLA) literature reports numerous studies of proficient second language (L2) speakers who diverge significantly from native speakers despite the evidence offered by the L2 input. Recent SLA theories have attempted to account for native speaker/non-native speaker (NS/NNS) divergence by arguing for the dissociation between syntactic knowledge and morpho(pho)nology. In particular, Lardiere (1998), Prevost and White (2000), and Goad and White (2004) claim that highly proficient learners have knowledge of the abstract syntactic properties of the language but occasionally fail to associate them with the correct morphological or phonological forms. On the other hand, theories that support partial availability of Universal Grammar (UG) (Tsimpli and Roussou 1991; Hawkins and Chan, 1997) argue for a problem in the syntax: while UG principles and operations are available in SLA, the formal features of the target language that are not instantiated in the L1 or have a different setting, cause learnability problems. This article discusses acquisitional data in the light of the Interpretability Hypothesis (Tsimpli and Mastropavlou, 2007), which is a reformulation of the SLA theory suggested by Tsimpli and Roussou (1991) in minimalist terms. It is argued that a minimalist approach to SLA can be implemented to specify the status of the features that are least accessible to re-setting in the SLA process, given (1) constraints on their learnability and (2), their setting in the L1 grammar. The phenomenon discussed concerns the use of the resumptive strategy in wh- subject and object extraction by intermediate and advanced Greek learners of English. It is proposed that the acceptability rate of pronouns in the extraction site is conditioned by the Logical Form (LF) interpretability of the features involved in the derivation. Hence, the interpretable features of animacy and discourse-linking are hypothesized to be involved in the analysis of English pronouns by Greek L2 learners, while the first language (L1) specification of resumptive pronouns as clusters of uninterpretable Case and Agreement features resists resetting. (Contains 7 tables, 2 figures and 12 footnotes.)