Antxon Olarrea is Professor in the Department of Spanish and Portuguese at the University of Arizona, where he has been teaching for over 20 years. He specializes in Syntax and Biolinguistics. He is author of Orígenes del Lenguaje y Selección Natural (2005); co-author of Romance Linguistics (2010) and The Handbook of Hispanic Linguistics (1994). He is the recipient of over a dozen local and national teaching awards.

Anna María Escobar is Professor of Spanish, Linguistics, French, and SLATE at the University of Illinois at Urbana-Champaign. She specializes in the socio-historical dynamics of morpho-syntactic and semantic change in language contact contexts. She has published two books on Andean Spanish (1990, 2000), co-written a book on Spanish of the U.S. (2015, with Kim Potowski), and edited a book on language contact in Latin America (2009, with Wolfgang Wölck). Presently, she is co-editing The Cambridge Handbook of Language Contact (with Salikoko Mufwene), co-editing a book on Spanish diversity in the Amazon (co-edited with Margarita Jara, Roberto Zariquiey and Pilar Valenzuela), and working on an historical sociolinguistic book project on the development of subjectivity and evidentiality in Spanish-Quechua contact.

Catherine Travis is Professor of Modern European Languages at the Australian National University. Her research addresses questions related to linguistic and social factors impacting on language variation and change, in particular in socially diverse communities. She is co-author of the book Bilingualism in the Community (2018, CUP), deriving from her NSF-funded research on Spanish in New Mexico, USA, and she is currently leading a project on variation and change in English spoken in Sydney, Australia, funded by the ARC Centre of Excellence for the Dynamics of Language in which she is a Chief Investigator.

Cristina Sanz is Professor of Spanish and Linguistics at Georgetown University, where she directs the Intensive and School of Foreign Service Spanish Programs, the Barcelona Summer Program, and is Coordinator of the Catalan Lectureship. Her area of expertise is multilingualism across the lifespan. She has published over 90 volumes, articles and chapters in such journals as Journal of Cognitive Neuroscience, PLoS ONE, Bilingualism Language and Cognition, Language Learning, and Applied Psycholinguistics. Her recent books include The Routledge Handbook of Study Abroad. Her 2005 volume with GU Press received the MLA's Mildenberger Award, and she is a recipient of the 2019 President's Awards for Distinguished Scholar-Teachers.