My research interests are in formal syntax and semantics, that is, in precisely characterizing the knowledge speakers have about the grammars of the languages that they speak and how they interpret utterances in their languages, and explaining why this knowledge is what it is in terms of theories of possible natural languages. I am primarily interested in the nature of word meanings and the role word meanings play in shaping the grammar of a language. My work addresses questions such as how word meanings are decomposed into more basic semantic primitives, how these primitives are interpreted truth conditionally, and how a word’s meaning correlates with and ultimately determines its grammatical behavior. I have a specific focus on the semantics of verbs and prepositions and the linguistic representation of events.  One of my longest standing research projects is in lexical aspect, i.e. how different words describe the ways events unfold over time. Connected to this is my work on affectedness and change-of-state, i.e. how languages describe cause and effect relations, and on motion descriptions, i.e. how languages describe something moving from one place to another. My work on these topics has also explored argument realization, which concerns the ways participants in events are expressed overtly in the clause. My most recent research has looked at the deeper foundations of what words can and cannot mean, exploring the ways that individual verb meanings fall into classes due to semantic similarity, but also how they differ in ways that distinguish verbs within the same class. I have also worked on issues of syntax that are less connected to lexical semantics, including the expression of coordination (e.g. expressions involving and and or), the structure of noun phrases, and pronominal systems. My work has a cross-linguistic component to it, including detailed studies of various phenomena in English, Colloquial Sinhala, Indonesian, Japanese, Korean, Romanian, and Spanish, plus works that are more explicitly typological in nature (i.e. that look at variation across many languages)