Ongoing projects, drafts, research topics, etc. I mostly work on topics that allow me to combine diachronic/historical research with theoretical linguistics, as well as on classic comparative-method-oriented Indo-European reconstruction, so there’s a certain amount of overlap between these projects.


  • Deponency in finite and non-finite contexts: Deponents (verbs with non-active morphology but active syntax) are a small class of form-function mismatch verbs that turn up in almost all languages with a “Greek-type” voice system, in which syncretic non-active voice morphology is found in anticausatives, reflexives, (medio)passives, self-benefactives, and generic/dispositional constructions (e.g., Ancient & Modern Greek, Sanskrit, Latin, and Hittite). Where do they come from, and why? The answer seems to lie in the fact that the postsyntactic voice morphology (in the sense of Embick 1998, 2004…) of these languages is “blind” to valency and thematic roles –  non-active morphology surfaces whenever Voice does not introduce an external argument (as argued by Embick and others). I have argued in my dissertation that deponents underwent a diachronic reanalysis that produced verbs with “low agents”: they have an agent argument, but it is base-generated in the wrong structural position (below Voice, the canonical position of the agent argument at least since Kratzer 1996). A revised and more detailed version of this proposal which draws on additional evidence from non-finite forms of deponent verbs is due to appear in Language (here’s the manuscript:
  • It’s even possible to reconstruct Proto-Indo-European deponents:
    • Reconstructing Proto-Indo-European deponents. Indo-European Linguistics 4/1 (2016), 98–149. DOI: 10.1163/22125892-00401001 IEUL_004_01_PIE deponents
    • Deponents in Vedic and Sanskrit display an unexpected “split” with respect to aspect (they’re predominantly found in the imperfective rather than the perfective stem), which I describe here: Grestenberger_Split deponency in PIE
  • A monograph of deponents is in the works as well (the working title is Deponency: a cross-linguistic perspective), scheduled to appear with Cambridge University Press in 2019. The aim is to strengthen the generalization/analysis I have proposed for deponent behavior in the verbal domain by adding further cross-linguistic evidence on finite and non-finite deponent forms in Indo-European and non-Indo-European languages.


Our intuitions concerning the “canonical function” of particular morphemes or constructions often run into trouble when we encounter the messiness and “exceptions” in languages past and present. For example, what are we to make of the fact that the –or ending in Latin am-or “I am loved” seems to signal passive voice, but the same ending in the Latin deponent verb hort-or “I encourage” is very much non-passive? We could just give up and decry the chaos that is natural language, but I prefer to seek a principled explanation for these “exceptions” based on general considerations of the mechanisms of the language faculty (“UG”) and the way language is acquired by speakers and changes over time. Synchronic “mismatches” between form and function are valuable clues both to the diachrony of a language (its development over time) and the synchronic properties of speakers’ grammars at any given point in time. I have implemented this approach in several publications (most recently, naturally, in my work on deponency):

  • Passives in Vedic and Ancient Greek: Both languages have developed designated passive morphemes that are not inherited from Proto-Indo-European in this function; in addition to the inherited non-active morphology which can be used to form passives (among other functions). Synchronically, these morphemes are odd – they are “too low” in the structure and co-occur with the inherited Voice morphology. I argue that this reflects their status as reanalyzed verbalizing morphemes, e.g., in: NELS 47 CG passives handout Vienna passives handout NELS 48 handout Carleton_two types of passive_27.1
  • Deponency in finite and non-finite contexts. Accepted for publication in Language (see above for the manuscript).
  • Number marking in German measure phrases and the structure of pseudo-partitives. Journal of Comparative Germanic Linguistics 18/2: 93–138. DOI 10.1007/s10828-015-9074-1.  Number marking in pseudo-partitives
    • Apparent mismatches between meaning and external syntax of measure nouns is due to differences in their structural make-up.
  • The Indo-Iranian cákri-type. Journal of the American Oriental Society 133.2: 269–293. The Indo-Iranian cakri-type_JAOS133.2
    • Indo-Iranian reduplicated i-stems *look* like they’re derived from the likewise reduplicated perfect stem, but lack the expected perfect(ive)/past meaning. That’s because they’re historically denominal and became associated with synchronic verbal stems relatively late.

Reconstruction of PIE morphology & syntax

Reconstructing the morphosyntax of Proto-Indo-European and its changes on the way to the attested Indo-European daughter languages is relevant not only for the field of comparative Indo-European linguistics, but for understanding morphological change and the diachrony of argument structure in general. Comparative Indo-European linguistics is almost exactly 200 years old, and our reconstructions are getting ever more refined and detailed – a rich source for comparison with other languages families, as well as with theoretical aspects of language change and the language faculty.

  • Participial morphology in Proto-Indo-European: Hannes Fellner and I propose a broad reconstruction of PIE “participial suffixes” and their functions, focusing on *-nt-, *-mh1no-, and *-to-, in the forthcoming proceedings of the Marburg 2015 conference on the decipherment of Hittite (Marburg_Fellner_Grestenberger). Not all of this is new, but we do show that the Tocharian participial morphology actually groups this branch closer to the “inner-IE” languages than to Hittite; and provide arguments that *-nt– was originally a stative/”adjectival passive” suffix that was reanalyzed as “active” suffix in inner-IE (based on work on Hittite by Michael Frotscher)
  • Voice and verbalizing morphology in PIE: What was the voice system of PIE like? Probably not that different from that of the oldest attested languages, despite what you may have heard. Building on Jay Jasanoff‘s reconstruction of the “proto-middle”, I have argued that it’s even possible to reconstruct “exceptions” to the expected distribution of non-active/”middle” morphology for PIE. Reconstructing exceptions may be seen as controversial, but if this was a natural language, shouldn’t we expect and detect a certain measure of idiosyncrasy (or “periphery”, to use a Chomskyan term) in our reconstructed proto-languages?
  • Ever since my University of Vienna M.A. thesis (Diplomarbeit_Version 2), I have been strangely fascinated by the nominal suffix *-i and its variety of functions in PIE, maybe because we find it in adjectives, derived nominals, and compounds alike. Its original function has been described as “substantivizing” or “individualizing” by Alan Nussbaum, and I’ve built on his analysis in several publications:
    • On “i-substantivizations” in Vedic compounds. In Hansen et al. (eds.), Usque ad radices. Indo-European studies in honour of Birgit Anette Olsen, 193–206. Museum Tusculanum. Festschrift Olsen_i-stem compounds
    • Zur Funktion des Nominalsuffixes *-i– im Vedischen und Urindogermanischen (“On the function of the nominal suffix *-i– in Vedic and proto-Indo-European”). Das Nomen im Indogermanischen: Morphologie, Substantiv versus Adjektiv, Kollektivum. Akten der Arbeitstagung der Indogermanischen Gesellschaft vom 14. bis 16. September 2011 in Erlangen, eds. N. Oettinger and Th. Steer. Wiesbaden: Reichert, 88–102. Akten_Erlangen_i-Stämme
    • The Indo-Iranian cákri-type. Journal of the American Oriental Society 133.2: 269–293. The Indo-Iranian cakri-type_JAOS133.2

Diachronic syntax

Applying insights from theoretical linguistics and syntactic theory to the observed changes in the (morpho)syntax of related language stages helps us understand the constraints on language change. In generative approaches, “language change” refers to changes that occur as speakers acquire grammar(s) during first language acquisition and (for reasons that remain hotly debated) end up with a slightly different grammar than the input grammar(s). These approaches greatly constrain the possible avenues of syntactic change. Some contributions to understanding syntactic change from a generative perspective include:

  • The development of participial morphology in Greek (and more generally in Indo-European): “Participle cycles” in the (pre-)history of Greek: losing
    and gaining functional structure, Participle_cycle_DiGS (to appear in Cycles in language change, eds. Lieven Danckaert et al., Oxford University Press), the proceedings paper for my talk at DiGS 18 (here are the slides:  DiGS18_slides )
  • Some aspects of my work on deponency (e.g., Deponency in finite and non-finite contexts, – deponents are synchronic exceptions to the canonical distribution of voice morphology; they therefore need a diachronic explanation (in terms of the reanalysis of their argument structure).
  • From inalienable possession to reflexivity: The development of Vedic tanū– ‘body’. Harvard Working Papers in Linguistics 30, 25–44. HWPL 30- Ved. tanU-



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