Ana Arregui is Associate Professor of Linguistics at the University of Ottawa. Her research is in the domain of natural language semantics, focusing on modality, tense, and aspect. Her publications include articles in Natural Language Semantics, Journal of Semantics, and Linguistics and Philosophy. She holds a Licenciatura en Letras from the University of Buenos Aires and a Ph.D in Linguistics from the University of Massachusetts, Amherst. María Luisa Rivero is Emeritus Professor of Linguistics at the University of Ottawa, and a Fellow of the Royal Society of Canada. Her research has focused on syntax and semantics, most recently paying particular attention to aspect, modality, and tense, with emphasis on languages of the Romance and Slavic families and those of the Balkan peninsula. Andrés Salanova is Associate Professor of Linguistics at the University of Ottawa. His research has concentrated on the structure of Mebengokre, a Jê language spoken in central Brazil, and his publications have looked at topics ranging from phonology to the semantics of aspect in that language. He has conducted field research in central Brazil since 1996, and is more broadly interested in the history and ethnography of the South American lowlands.