Thesis (Ph.D.) - Indiana University, Department of Spanish and Portuguese, 2021The present study examines the usage and language attitudes toward polymorphism of second person singular forms (2PS) in the Spanish of Medellin, Colombia. Several researchers have observed polymorphism and have reported that it occurs due to the situational context and the intention of the speaker. However, no study has systematically examined all cases of polymorphism. The present study addresses this gap by focusing explicitly on polymorphism as the dependent variable. Additionally, no previous study has examined implicit language attitudes toward polymorphism. With this in mind, the current study examines explicit and implicit language attitudes toward polymorphism of 2PS across three Colombian populations: speakers from Medellin, Bogota, and Cali. A total of 72 speakers from Medellin completed three tasks: an oral discourse completion task (DCT), a soap opera perception task, and a matched guise. In addition, 24 participants from Cali and 24 from Bogota also completed the latter two tasks. Results show that polymorphism is common in Medellin Spanish as it occurred 23% of the time. In addition, polymorphism was favored by three variables: change in speech act, intimate interlocutors, and male speakers. It was observed that most cases of polymorphism consisted of one switch between tú and usted or usted and tú and no explicit subject pronouns. Regarding implicit language attitudes, findings indicate that for paisas, most of the time there were no significant differences between polymorphism and unimorphism stimuli. Importantly, ratings of polymorphism varied greatly depending on stimulus; unimorphism was evaluated higher than polymorphism for stimuli 1 and 2 but the opposite was found for stimulus 3. In general, paisas tended to rate the matched guise stimuli more positively than bogotanos and caleños, and this was especially the case for the polymorphism stimuli. Most speakers did not notice the polymorphism in the telenovela task until their attention was explicitly directed to it. In sum, the data confirm that polymorphism is a useful tool that speakers take advantage of to express different speech acts. Findings are discussed in terms of broader connections to polymorphism in general and pedagogical implications, contributing to the fields of variationist sociolinguistics and second language acquisition.