The present study investigated the comprehension of Spanish accusative (direct object) and dative (indirect object) clitic pronouns in OVS strings by a cross-section of L2 learners reaching advanced levels of proficiency. Statistical analyses yielded novel findings regarding the use of the first noun strategy during on-line processing of aural input. Nativelike assignment of grammatical roles to object pronouns was promoted by pragmatic factors at early levels of proficiency and by varying linguistic factors as proficiency increased. The morphological markers promoting nativelike OVS processing were person, then case, followed by gender. Development was guided by a one-to-one principle of form-function mapping; grammatically non-homophonous forms were processed accurately before homophonous forms.