Sag 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 head-driven phrase structure grammar as well as generalized phrase structure grammar, HPSG's immediate intellectual predecessor. Later, he worked on Sign-Based Construction Grammar, which blended HPSG with ideas from Berkeley Construction Grammar. He was the author or co-author of 10 books and over 100 articles.In general, his research late in life primarily concerned constraint-based, lexicalist models of grammar, and their relation to theories of language processing. Sag was the Sadie Dernham Patek Professor in Humanities, Professor of Linguistics, and Director of the Symbolic Systems Program 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 for distinguished contributions to the field of linguistics. He was honored by a volume of studies published in 2013 in his honor, The Core and the Periphery: Data-Driven Perspectives on Syntax Inspired by Ivan A. Sag, edited by Philip Hofmeister and Elisabeth Norcliffe.
Selected publications
Sag, Ivan A. 1980. Deletion and Logical Form. New York:Garland Press.
Pollard, Carl, and Ivan A. Sag. 1987. Information-Based Syntax and Semantics; Volume One - Fundamentals. CSLI Lecture Notes Series No. 13. Stanford: CSLI Publications. Distributed by University of Chicago Press.
Nunberg, Geoffrey, Ivan A. Sag, and Thomas Wasow. 1994. "Idioms." Language 70:491– 538.
Pollard, Carl, and Ivan A. Sag. 1992. "Anaphors in English and the Scope of Binding Theory." Linguistic Inquiry 23.2:261–303.
Miller, Philip, and Ivan A. Sag. 1997. "French Clitic Movement Without Clitics or Movement." Natural Language and Linguistic Theory 15:573–639.
Sag, Ivan A. 1997. "." Journal of Linguistics 33.2:431–484.
Jonathan Ginzburg and Ivan A. Sag. 2000. Interrogative Investigations: the form, meaning, and use of English Interrogatives. Stanford: CSLI Publications.
Bouma, Gosse, Robert Malouf, and Ivan A. Sag. 2001. "Satisfying Constraints on Extraction and Adjunction." Natural Language and Linguistic Theory 19.1:1–65.
Kim, Jong-Bok, and Ivan A. Sag. 2002. "French and English Negation without Head-Movement." Natural Language and Linguistic Theory 20.2:339-412.
Sag, Ivan A., Thomas Wasow, and Emily Bender. 2003. Syntactic Theory: A formal introduction. Second edition. Stanford: CSLI Publications.