The goal of this study is to analyse both the use of lo and null object to refer to third person direct objects in an oral corpus of Quechua-Spanish bilinguals from the district of Chinchero (Cuzco). The analysis was performed through qualitative and quantitative methods that allowed us to show which parameters favour their use. We set this goal because our corpus's direct object marking system is characterized by two variants: the use of lo as the only third person direct object pronoun, i.e. as an invariable morph, and its omission, i.e., the production of a zero morph. Through a multivariate statistical analysis we tried to predict the factors favouring the use of the full form and the null morpheme, and also to create a scale to account for the weight of each factor. The results show that the selection of lo or zero is triggered by different semantic, syntactic, and discursive factors. This reveals the existence of a highly productive and efficient discursive resource. Finally, we put forward that these changes belong to a pronominal system reorganization process caused by the bilingual situation of the region, and an intense contact with Quechua. In this context, we believe that both linguistic and social factors are essential to the development and diffusion of these changes.
