He completed his PhD in Semantics at MIT, but his work also touches on syntax, pragmatics and discourse. The topic of his dissertation was possible world and tense semantics, especially as it pertains to the de re and de dicto interpretation of noun phrases. He has also done research on scalar implicature, anaphora, focus, and conditionals. Prof. Keshet regularly teaches the graduate-level Introduction to Semantics in the linguistics department and has taught seminars on discourse anaphora and focus/information structure.