Experimental second language acquisition research typically investigates the effectiveness of instruction in terms of overall group gains. A particular instructional method may not, however, benefit all learners uniformly. This study, conducted in a New Zealand secondary school, establishes whether there is any relationship between the effectiveness of three instructional methods, and learner aptitude. Students (n = 60) were assigned to one of three groups (deductive instruction group, inductive instruction group, structured input instruction group) and received instruction that targeted direct object pronouns in L2 French. All students were assessed on the following three measures of language aptitude: (a) language analytic ability, (b) phonemic coding ability and (c) working memory. Results indicate that deductive instruction that gives students opportunities to produce language output may neutralize individual differences in language aptitude. (Contains 3 notes and 12 tables.)