This pioneering comparative study provides the first quantitative, large-scale, cross-language analysis of subject pronoun variation, with a dataset representing more than 1000 speakers, twenty-four communities, and 6 languages: Persian, Spanish, European and Brazilian Portuguese, Mandarin, and Swabian. Over 250,000 sites of pronominal variation are analysed to reveal community-specific and universal patterns of pronoun use, providing readers with key insights into how communities vary in their characteristic rates of pronoun use and in their sensitivity to linguistic and social conditioning factors. The project employs a range of quantitative measures, statistical techniques, and visualization tools to assist readers in investigating pronominal variation from cognitive, linguistic, and social perspectives. The book includes a freely downloadable R Markdown Project for readers to use in replicating and extending the methods provided to their own projects.