I have a passionate obsession to study environments in which people use more than one language, and in particular to seek out the linguistic factors that favor or impede language mixing. Beginning with my early research on Spanish-English codeswitching in the United States, I have examined past and present contact environments involving Spanish and Portuguese around the world. An unrepentant formalist trained as a mathematician, I inform my theorizing with data obtained from grassroots speech communities in which the roles of prescriptivism, literacy, and sociolinguistic insecurity are minimal. Since my laboratory is the "big one," I complement traditional field linguistics methods with experimental techniques adapted to work "outside the walls." Although at one point or another in my career I have collected data from just about everywhere Spanish is spoken and have published many interpretive studies, my most recent lines of inquiry have involved Spanish/Palenquero (the Afro-Hispanic creole language of San Basilio de Palenque, Colombia), Quichua/Media Lengua (a mixed language of northern Ecuador), and Spanish/Portuguese (northeastern Argentina).
My CLS research group profile: https://cls.la.psu.edu/research/language-contact-in-the-field
A list of published studies can be found in my curriculum vitae, and many of the publications are posted in .pdf format on this web site.
Spanish-English bilingualism in the United States
Spanish-Portuguese language mixing
The history of Afro-Hispanic language
Contemporary Afro-Hispanic language
Philippine Creole Spanish (Chabacano)
Andean Spanish-Quechua contact phenomena