It is well established that part of native speaker competence resides in knowledge of conventionalized word combinations, or nativelike selections (NLSs). This article reports an investigation into the receptive NLS knowledge of second language (L2) users of English in both the United Kingdom and Poland and the influence of a variety of independent variables on this knowledge. Results indicate that only an early start (< 12 years old) in an immersion setting guarantees nativelikeness. Long exposure in late starters brings moderate gains in both settings but not to nativelike levels; positive feelings toward the L2 and motivation to interact in it bear little to no relationship with NLS; phonological short-term memory (pSTM) is the only predictor of NLS ability in immersion late starters, with no effect found in a foreign language setting. Our results suggest that NLS is subject to age effects and that, for late starters, a good pSTM and L2 immersion are necessary for the acquisition of this dimension of L2 knowledge.