Anyone who has studied linguistics in the last half-century has been affected by the work of David Perlmutter. One of the era’s most versatile linguists, he is perhaps best known as the founder (with Paul Postal) of Relational Grammar, but he has also made contributions to areas ranging from theoretical morphology to sign language phonology. Hypothesis A/Hypothesis B (the title evokes Perlmutter’s characteristic style of linguistic argumentation) offers twenty-three essays by Perlmutter’s colleagues and former students. Many of the contributions deal with the study of the world’s languages (including Indo-European languages, sign language, and languages of the Americas), reflecting the influence of Perlmutter’s cross-linguistic research and meticulous analysis of empirical data. Other topics include grammatical relations and their mapping; unaccusatives, impersonals, and the like; complex verbs, complex clauses, and Wh-constructions; and the nature of sign language. Perlmutter, currently Professor Emeritus at the University of California, San Diego, and still actively engaged in the field, opens the volume with the illuminating and entertaining essay, “My Path in Linguistics.”ContributorsJudith Aissen, Mark Aronoff, Leonard H. Babby, Nicoleta Bateman, J. Albert Bickford, Sandra Chung, William D. Davies, Stanley Dubinsky, Katarzyna Dziwirek, Patrick Farrell, Donald G. Frantz, Donna B. Gerdts, Alice C. Harris, Brian D. Joseph, Géraldine Legendre, Philip S. LeSourd, Joan Maling, Stephen A. Marlett, Diane Lillo-Martin, James McCloskey, Richard P. Meier, Irit Meir, John C. Moore, Carol A. Padden, Maria Polinsky, Eduardo P. Raposo, Richard A. Rhodes, Wendy Sandler, Paul Smolensky, Annie Zaenen