He has been working primarily on Nuuchahnulth (a Wakashan language spoken in British Columbia, Canada), and his research interests include morphology, syntax, interactions between grammar and discourse, grammatical typology, and language documentation. Among the main publications are books on Nuuchahnulth, Nuuchahnulth (Nootka) Morphosyntax (2001, University of California Press) and two text collections with grammatical analyses (2003, Endangered Languages of the Pacific Rim Project, Osaka).