Mark Davies, Professor of Linguistics / Brigham Young University http://davies-linguistics.byu.edu/ Large, robust corpora allow us to map linguistic changes in languages, in ways that would have been considered impossible just 10-20 years ago. In this presentation, I will examine how the Corpus del Español (100 million words, 1200s-1900s) and the Corpus do Português (45 million words, 1300s-1900s) can be used to examine a wide range of linguistic changes -- lexical, morphological, syntactic, and semantic. I will also compare these resources with corpora that allow a much smaller range of searches, such as the CORDE from the Real Academia Española. Finally, I will look at the new googlebooks.byu.edu interface, which allows access to 45 *billion* words of Spanish from the 1500s-2000s. This improves greatly on the standard, simple Google Books interface, and it also allows for research on an extremely wide range of changes in Spanish.