Ivan Sag (born November 9, 1949 in Alliance, Ohio) is an American linguist and cognitive scientist. He is the Sadie Dernham Patek Professor in Humanities, Professor of Linguistics, and Director of the Symbolic Systems Program[1] at Stanford University. A fellow of the American Academy of Arts and Sciences and the Linguistic Society of America, in 2005 he received the LSA's Fromkin Prize[2] for distinguished contributions to the field of linguistics.
Sag has made notable contributions to the fields of syntax, semantics, pragmatics, and language processing. His early work was as a member of the research teams that invented and developed HPSG as well as generalized phrase structure grammar, HPSG's immediate intellectual predecessor. Sag's current research primarily concerns constraint-based, lexicalist models of grammar, and their relation to theories of language processing. He is the author or coauthor of 10 books and over 100 articles.
Sag received his PhD from MIT in 1976, writing his dissertation (advised by Noam Chomsky) on ellipsis. He received an MA from the University of Pennsylvania, where he studied comparative Indo-European languages, Sanskrit, and sociolinguistics, and a BA from the University of Rochester.