Underspecified <i>they</i> becomes specified early in sentence processing

We investigated underspecification in sentence processing, using the ambiguous pronoun <i>they</i> as a case study. We asked whether <i>they</i> is processed as underspecified for number, and probed into when it acquires its number specification in incremental processing. A key question we address is whether underspecification is due to the fact that the pronoun is lexically underspecified for number or due to shallow processing. Based on the findings from an acceptability judgment study and two reading time studies using the Maze task, we conclude that <i>they</i> is lexically underspecified for number and that the processor homes in on a more enriched specification of <i>they</i> early, soon after it links with its antecedent and before fully disambiguating material is encountered. The data suggest that readers will develop detailed commitments to semantic representations for ambiguous expressions early in processing. We discuss how this finding stands in contrast to underspecified plural definite descriptions.