Diane Brentari's broad interests address issues in sign language grammars, particularly problems at the intersection of morphology, phonology, and prosody. Her work has primarily focused on sign language phonology as a way to understand the effects of communication mode (or modality) on language, as well as the flexibility of the human language capacity in constructing spoken and signed languages. Her current research involves language variation among sign languages, and how the mental lexicon emerges in historical time, which includes the relationship between gesture, homesign systems, and well-established sign languages. Brentari is one of three Directors of the Center for Gesture, Sign and Language and is the Director of the Sign Language Linguistics Lab.