This paper reports on two studies that investigated the effectiveness of a contrastive analysis type of pedagogical intervention, which aimed to promote interlanguage development in the use and understanding of English possessive determiners (PDs) among adolescent second language (L2) learners. The first research question asked whether explicit instruction involving a rule of thumb, contrastive information and repeated contextualised practice of the rule would allow learners with French and Catalan/Spanish native languages in "regular" limited-exposure programmes to make progress in using and understanding English PDs. The findings in both contexts confirm that this type of form-focused instruction, which had proven successful in more acquisition-rich contexts, could also help school learners in "drip feed" instructional settings extract greater benefit from their limited contact with the L2. The second research question asked whether the developmental framework for the acquisition of English PDs, originally created to account for francophone learners' acquisition, was valid for other L2 populations. The findings demonstrate that it also explains patterns of development among Catalan/Spanish learners. The results of the two studies point to criteria that may be relevant in determining the type, timing and approach for focused pedagogical intervention in limited-exposure programmes.