This article investigates the second language (L2) acquisition of two expressions of the semantic feature [definite] in Russian, a language without articles, by English and Korean native speakers. Within the Feature Reassembly approach (Lardiere, 2009), Slabakova (2009) has argued that reassembling features that are represented overtly in the first language (L1) and mapping them onto those that are encoded indirectly, or covertly, in the L2 will present a greater difficulty than reassembling features in the opposite learning direction. An idealized scale of predictions of difficulty is proposed based on the overt or covert character of the feature encoding and the ease/difficulty of noticing the feature expression. A total of 158 participants (56 native Russian, 49 English learners and 53 Korean learners of Russian) evaluated the acceptability of test sentences in context. Findings demonstrate that acquiring the expression of a feature that is encoded contextually in the L2 is challenging for learners, while an overt expression of a feature presents less difficulty. On the basis of the learners’ developmental patterns observed in the study, we argue that overt and covert expression of semantic features, feature reassembly, and indirect encoding appear to be significant factors in L2 grammatical feature acquisition.