LAUSR

Abstract The vocabulary of human languages has been argued to support efficient communication by optimizing the trade‐off between simplicity and informativeness. The argument has been originally based on cross‐linguistic analyses of vocabulary in semantic domains of content words, such as kinship, color, and number terms. The present work applies this analysis to a category of function words: indefinite pronouns (e.g., someone, anyone, no one). We build on previous work to establish the meaning space and featural make‐up for indefinite pronouns, and show that indefinite pronoun systems across languages optimize the simplicity/informativeness trade‐off. This demonstrates that pressures for efficient communication shape both content and function word categories. In doing so, our work aligns with several concurrent studies exploring the simplicity/informativeness trade‐off in functional vocabulary. Importantly, we further argue that the trade‐off may explain some of the universal properties of indefinite pronouns, thus reducing the explanatory load for linguistic theories.