Rena Torres Cacoullos is Professor of Spanish and Linguistics in Penn State. She looks for quantitative patterns in everyday language use. She teaches the grammatical variation across the Spanish-speaking world, cognitive and social factors in language change, and grammar from a usage-based perspective. Co-author of Bilingualism in the Community: Code-switching and Grammars in Contact, in her most recent research Dr. Torres Cacoullos tries to understand language variability and changeability across bilingual speakers. Her studies show that bilinguals who regularly use both their languages are adept at keeping them connected, yet separate.