I'm a historical linguist, with an interest in all aspects of language change. More specifically, though, I'm an Indo-Europeanist — a specialist in the Indo-European (IE) family and the development of the early IE languages from their reconstructed parent, Proto-Indo-European (PIE). Some of the particular problems and projects I'm working on, or have recently worked on, are described below.
Architecture of the PIE verbal system
Starting with a paper that I wrote in 1978-79, I've been developing a model of the PIE verbal system that tries to account for the discrepancies between the "classical" picture of the PIE verb and the surprisingly aberrant facts of Hittite and Anatolian. The fruits of these efforts are presented in my 2003 book, Hittite and the Indo-European Verb (HIEV), which (inter alia) documents the case for a PIE "h2e-conjugation" alongside the familiar "mi-conjugation." The "h2e-conjugation theory" has given rise to a certain amount of controversy. The journal Kratylos, for example, devoted two long reviews to HIEV in its 2006 issue, one highly positive (by J.-L. García Ramón) and the other highly negative (by N. Oettinger). Most other competent reviewers have been positive. Readers are invited to form their own opinion.
Prehistory of PIE morphology
As our understanding of PIE grammar deepens, new aspects of the prehistory of PIE become accessible through internal reconstruction. In a recent paper, I examine the structure of the plural cases of the noun and pronoun and find evidence for a number of obsolete endings, including a dative plural in *-os, an instrumental plural *-is, and a pronominal neuter plural in *-oi. An unlooked-for byproduct of this study was the emergence of a new "Indo-Hittite" isogloss — an innovation common to the IE languages other than Anatolian. Other work, still in progress, builds on the findings of HIEV to study the basis for the distinction between the mi- and h2e-endings in the verb — a project that promises to have consequences for our understanding of PIE case syntax.
In recent years I have begun to look into the historical origins of the Baltic and Slavic accent and intonation systems — a complex and intriguing field that has tended to be neglected by general Indo-Europeanists. My interest in this area grew out of my need to use Lithuanian and Slavic accentual evidence in my work on the PIE verb. Despite a century of impressive scholarship on Proto-Baltic, Proto-Slavic, and the individual Baltic and Slavic languages, remarkably little is known about the PIE background of some of the most basic BS features. A case in point is BS paradigmatic "mobility," a phenomenon unrelated to the superficially similar accent movement effects seen in Greek and Sanskrit. In a series of recent papers, I outline a solution to this problem that is unusual in giving "equal time" to nouns and verbs.
Problems in the individual languages
Since the purpose of reconstructing a parent language is to illuminate the history of its descendants, part of my work is devoted to shedding light on unexplained facts in the IE daughter languages. I have often been drawn to "classic" problems, such as the origin of the Latin gerund(ive) and the class VII strong verbs of Northwest Germanic, on both of which I have recently published papers. I have also written extensively on "e¯-statives" around the family (the topic of my 1978 monograph, Stative and Middle in Indo-European), and on the sigmatic forms of the Italic and Celtic verb. Other problems that have interested me over the years include Lachmann's Law in Latin, the declension of the word for "woman" in Old Irish, the gendered 1 sg. pronoun in Tocharian, and the origin of the "ā-preterite" in Baltic and Slavic.
Indo-European Linguistics: A New Introduction
My former student Michael Weiss (Cornell University) and I are writing a new introduction to IE linguistics, to be published by Oxford University Press. The book we are planning will not be a textbook, but a medium-length reference grammar of PIE, on approximately the same scale as Szemerenyi's badly outdated Introduction to Indo-European Linguistics (1996, but based on a German original of 1970). Our aim is to present a coherent picture of the parent language that reflects consensus views where possible, but that gives full coverage to the range of conflicting opinions on the many individual questions, particularly in the area of morphology, where no consensus exists.