Subject pronoun interpretation in native Spanish has generally been approached under the Position of Antecedent Strategy, a parsing strategy which claims that null pronouns bias toward subject antecedents and overt pronouns toward object antecedents. While some studies align with the predicted patterns, others present mixed evidence. To further clarify this, our study tests the offline interpretation of null and overt subject pronouns in 55 native Peninsular Spanish speakers. We additionally tested the role played by different temporal subordinating conjunctions (mientras “while” vs. cuando “when”) in modulating subject pronoun interpretation preferences. Our findings reveal that overt pronouns bias toward object antecedents independently from the subordinating conjunction. Conversely, null pronouns bias toward subject antecedents, but their interpretation is influenced by the type of subordinating conjunction, with higher rates of subject interpretations in the mientras “while” condition. These results lend support to theoretical accounts such as the Form-Specific Multiple-Constraints approach, which asserts that referring expressions are subject to different constraints and to varying degrees. These findings thus extend beyond purely structural accounts and underscore the complexity of subject pronoun interpretation in Spanish.

The recent hypothesis that L1 attrition affects the ability to process interface structures but not knowledge representations (Sorace, 2011) is tested by investigating the effects of recent L1 re-exposure on antecedent preferences for Spanish pronominal subjects, using offline judgements and online eye-tracking measures. Participants included a group of native Spanish speakers experiencing L1 attrition (‘attriters’), a second group of attriters exposed exclusively to Spanish before they were tested (‘re-exposed’), and a control group of Spanish monolinguals. The judgement data shows no significant differences between the groups. Moreover, the monolingual and re-exposed groups are not significantly different from each other in the eye-tracking data. The results of this novel manipulation indicate that attrition effects decrease due to L1 re-exposure, and that bilinguals are sensitive to input changes. Taken together, the findings suggest that attrition affects online sensitivity with interface structures rather than causing a permanent change in speakers’ L1 knowledge representations.