The question of how to account for the use and interpretation of overt versus null subject pronouns (SPs) in [+pro-drop] languages like Spanish is central to the study of discourse anaphora and of reference in general. It is a complex problem, given the fact that grammatical, semantic, pragmatic, cognitive, and socio-dialectal/contact factors can influence speakers' choice of null versus overt SPs. Numerous studies on SP expression in different varieties of Spanish have been carried out from a variationist perspective, while in second language acquisition the majority of work on the acquisition of Spanish null/overt SPs has been from a generative perspective and has not examined pragmatic rules. The present study examines the pragmatic contexts for Spanish null and overt subject pronoun (SP) use in native Spanish speakers' oral narratives, focusing on Spanish first person singular references with tensed verbs. Based on earlier work on SP expression and discourse anaphora in Spanish, a set of pragmatic rules of SP use is defined in terms of pragmatic and discourse notions. The rules proposed attempt to provide a more explanatory account for SP use. Subsequently, an examination of learner narratives was conducted in order to ascertain to what extent L2 speakers of Spanish acquire these pragmatic rules, which are rarely if ever taught. By approaching the problem from a pragmatic perspective and examining discourse constraints that govern acquisition and usage, this study intends to respond to a gap in our understanding of Spanish native speaker knowledge and L2 development of null and overt SPs.