This variationist study of subject pronoun expression (SPE) in Medellín, Colombia uses multivariate regressions to probe the effects of ten predictors on 4623 tokens from the Proyecto para el Estudio Sociolingüístico del Español de España y de América (PRESEEA) corpus. We implement analytical innovations by exploring transitivity and the lexical effect of the verb, which we analyze by testing infinitives and subject pronoun + verb collocations, respectively, as standalone, random-effect factors. Our results reveal the highest pronominal rate (28%) found in a mainland Spanish-speaking community. Additionally, we uncover that pronominal rates increase with age, a finding which appears to have cognitive implications. The internal conditioning contributes to pronombrista studies by showing the effects of discourse type and transitivity. Narratives and opinion statements favor overt subjects, but statements indicating routine activities favor null subjects. Whereas unergative verbs promote overt subjects, reflexive verbs favor null subjects. The lexical effect of the verb reveals opposing tendencies between verbs in the same category as well as within different collocations of the same verb, providing more definitive answers than the semantically guided approaches used for the last four decades and showing that verb groupings do not constitute functional categories with regard to SPE. Overall, this study contributes to expand our baseline knowledge of SPE in mainland Latin American communities and opens interesting research avenues.