About

Stefan Keine is an Associate Professor in the Department of Linguistics at the University of California, Los Angeles, where he also serves as Vice Chair and Director of Graduate Studies. His research focuses on syntactic theory, including topics such as clause-internal successive cyclicity, movement, cyclic Agree, and the architecture of syntax. He has contributed extensively to the understanding of syntactic phenomena through numerous publications, including monographs, edited volumes, and articles in leading linguistic journals. His work often explores the interaction of syntactic features, agreement, and movement, with particular attention to cross-linguistic variation and the typology of syntactic structures. Stefan Keine's research also involves the investigation of locality domains in syntax, the role of probes, and the typology of movement phenomena such as long-distance agreement and scrambling. His contributions have advanced the theoretical understanding of minimalism, feature sharing, and the syntactic behavior of languages like Hindi-Urdu, Irish, and German. He holds a prominent position in the field of generative syntax, with a focus on the formal properties of syntactic structures and their cross-linguistic variation.

Research topics

• Natural Language Processing
• Computer Science
• Artificial Intelligence
• Philosophy
• Linguistics
• Physics
• Geology
• Astronomy
• Epistemology
• Mathematics

Selected publications

• Silencing the PCC

  Linguistic Inquiry · 2026-03-20

  articleOpen access1st authorCorresponding

  Abstract Basque displays what is known as the Strong Person Case Constraint (PCC): an absolutive DP may generally not be 1st or 2nd person if it is c-commanded by a dative DP. We make the novel observation that this restriction is obviated under verbal ellipsis, even if this ellipsis does not affect the DPs whose cooccurrence is normally ruled out. We then explore the consequences of this generalization for accounts of the PCC. First, it indicates that the PCC arises from properties of the verb agreement, not of the DP arguments. Second, a comprehensive account of the Basque PCC must be sensitive to both narrow-syntactic and PF properties (in particular whether or not the verb agreement is pronounced). We then develop an account of the Basque PCC based on Coon and Keine’s (2021) feature-gluttony proposal. On this account, the Basque PCC results from an irresolvable conflict that arises in the morphological realization of a probe that has agreed with two DPs. We show that such an account offers a principled explanation of both the syntactic factors and the PF factors that condition the Basque PCC, in particular its interaction with verbal ellipsis.

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• Clause-internal successive cyclicity: Phasality or DP intervention?

  Natural Language & Linguistic Theory · 2025-04-22 · 7 citations

  articleOpen access1st authorCorresponding

  Abstract The well-known requirement that movement must proceed successive-cyclically through intermediate landing sites is standardly attributed to the presence of locality domains (phases) along the extraction path. Correspondingly, the existence of clause-medial intermediate landing sites is commonly taken as evidence for the existence of a clause-medial phase. In this paper, we argue that at least some instances of successive cyclicity through clause-medial positions are better understood as the result of intervention by the external-argument DP, not phasehood. Building on recent proposals about the principles that govern the behavior of complex probes, we propose that C in these cases can only attract the structurally closest DP. Elements separated from C by an intervening DP must first move around the intervening DP (“leapfrogging”). In languages where such leapfrogging is impossible, a local-subject-only extraction restriction arises; in a language where such leapfrogging is possible, extracting elements across the local subject is possible but must proceed through a clause-medial intermediate position, resulting in successive cyclicity. Evidence for this shift away from absolute locality domains like clause-medial phases to a DP-intervention account includes: (a) the reflexes of successive cyclicity being selective, arising with some elements but not others, (b) the distribution of the effect not correlating with whether an element is vP-internal or vP-external, but with whether a DP intervenes between this element and C, and (c) extraction patterns in unaccusatives.

  PublisherOA PDFDOI

• Not all reconstruction effects are syntactic

  Natural Language & Linguistic Theory · 2024 · 19 citations

  Senior authorCorresponding
  • Computer Science
  • Artificial Intelligence
  • Natural Language Processing

  Abstract This paper argues that not all reconstruction effects can be reduced to a syntactic mechanism that selectively interprets copies at LF. The argument is based on the novel observation that some but not all reconstruction effects induce Condition C connectivity in Hindi-Urdu. We contend that Hindi-Urdu requires the hybrid approach to reconstruction developed on independent grounds by Lechner (1998, 2013, 2019), where both copy neglect (a syntactic mechanism) and higher-type traces (a semantic mechanism) are available as independent interpretive mechanisms. We show that the interaction of these two modes of reconstruction derives the intricate reconstruction facts in Hindi-Urdu.

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• Movement and cyclic Agree

  Natural Language & Linguistic Theory · 2022-07-29 · 6 citations

  articleOpen access1st authorCorresponding

  Abstract Recent work has argued for derivational expansion of the search space of ɸ-probes as a result of the cyclic interaction of Merge and Agree (cyclic Agree). Empirical evidence for such effects has come from the interaction of Agree with external Merge, but these accounts make the additional predictions that such interactions should also arise from the interaction of Agree with movement. In this paper, we argue based on evidence from Hindi-Urdu that movement may feed cyclic Agree in the same way as external Merge, bearing out this key prediction. The central empirical generalizations that we argue for are that (i) A-scrambling of an object over a subject may feed agreement in certain configurations, (ii) there is nonetheless a preference for agreement with the structurally lower subject, and (iii) $\overline {\text{A}}$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover><mml:mtext>A</mml:mtext><mml:mo>‾</mml:mo></mml:mover></mml:math> -scrambling of the object never feeds agreement. We develop a cyclic-Agree analysis that provides a principled explanation of these generalizations. Crucial to this explanation are that (i) search space is dynamic and interacts with movement, (ii) there is a preference for agreement with elements c-commanded by the head that hosts the probe (first-cycle Agree), and (iii) ɸ-probes project as part of the label, but not past the immediate projection line of the head.

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• More on (the Lack of) Reconstruction in English <i>Tough</i>-Constructions

  Linguistic Inquiry · 2022-10-07 · 1 citations

  articleOpen accessSenior authorCorresponding

  This squib presents three new arguments that the matrix subject in English tough-constructions cannot reconstruct into the embedded gap. The first two arguments reexamine data in the literature purported to show such reconstruction. Upon closer scrutiny, we argue that these data in fact involve short reconstruction below a modal or generic operator in the matrix clause, and not genuine long reconstruction into the embedded gap. The third argument is that property positions, which independently require reconstruction, are unable to host tough-gaps. This ban on long reconstruction in English tough-constructions follows without further ado on a base-generation analysis.

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• COLLOQUIUM-Morphology of extraction: Reappraising vP phases

  OSF Preprints (OSF Preprints) · 2020-04-07

  articleSenior author
  Publisher

• Probes and Their Horizons

  The MIT Press eBooks · 2020 · 42 citations

  1st authorCorresponding
  • Geology
  • Physics
  • Astronomy

  A comprehensive theory of selective opacity effects—configurations in which syntactic domains are opaque to some processes but transparent to others—within a Minimalist framework. In this book, Stefan Keine investigates in detail “selective opacity”— configurations in which syntactic domains are opaque to some processes but transparent to others—and develops a comprehensive theory of these syntactic configurations within a contemporary Minimalist framework. Although such configurations have traditionally been analyzed in terms of restrictions on possible sequences of movement steps, Keine finds that analogous restrictions govern long-distance dependencies that do not involve movement. He argues that the phenomenon is more widespread and abstract than previously assumed. He proposes a new approach to such effects, according to which probes that initiate the operation Agree are subject to “horizons,” which terminate their searches. Selective opacity effects raise important questions about the nature of locality in natural language, the representation of movement-type asymmetries, correlations between clause structure and locality, and possible interactions between syntactic dependencies. With a focus on in-depth case studies of Hindi-Urdu and German, Keine offers detailed investigations of movement dependencies, long-distance agreement, wh-dependencies, the A/A' distinction, restructuring, freezing effects, successive cyclicity, and phase theory. Keine's account offers a thorough understanding of selective opacity and the systematic overarching generalizations to which it is subject.

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• Feature Gluttony

  Linguistic Inquiry · 2020 · 42 citations

  Senior authorCorresponding
  • Computer Science
  • Natural Language Processing
  • Artificial Intelligence

  This article develops a new approach to a family of hierarchy-effect-inducing configurations, with a focus on Person Case Constraint effects, dative-nominative configurations, and copula constructions. The main line of approach in the recent literature is to attribute these effects to failures of ϕ-Agree or, more specifically, failures of nominal licensing or case checking. We propose that the problem in these configurations is unrelated to nominal licensing, but is instead the result of a probe participating in more than one Agree dependency, a configuration we refer to as feature gluttony. Feature gluttony does not in and of itself lead to ungrammaticality; rather, it can create irresolvably conflicting requirements for subsequent operations. We argue that in the case of clitic configurations, a probe that agrees with more than one DP creates an intervention problem for clitic doubling. In violations involving morphological agreement, gluttony in features may result in a configuration with no available morphological output.

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• Locality Domains in Syntax: Evidence from Sentence Processing

  Syntax · 2020-05-07 · 20 citations

  article1st authorCorresponding

  Abstract One of the main discoveries of generative syntax is that long‐distance extraction proceeds in a successive‐cyclic manner, in that these dependencies are comprised of a sequence of local extraction steps. This article provides support for this general picture by presenting novel parsing evidence for intermediate landing sites created by successive‐cyclic movement, and it uses this parsing evidence to investigate the distribution of intermediate gaps. The central findings of this article are that (i) there is evidence that successive‐cyclic movement targets the edge of CPs and that (ii) there is no comparable evidence for an intermediate landing site at vP edges. These findings are fully consistent with the classical view of successive cyclicity, according to which only finite‐clause edges host intermediate landing sites. In the context of phase theory, these results receive a straightforward explanation if CPs are phases but vPs are not. The processing evidence presented here thus provides a novel diagnostic for the distribution of phases and new evidence for their active role in online sentence processing.

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• Hierarchy effects in copula constructions

  The Canadian Journal of Linguistics / La revue canadienne de linguistique · 2019-10-23 · 8 citations

  article1st authorCorresponding

  Abstract This paper develops a generalization about agreement in German copula constructions described in Coon et al. (2017), and proposes an analysis that ties it to other well-established hierarchy phenomena. Specifically, we show that “assumed-identity” copula constructions in German exibit both person and number hierarchy effects, and that these extend beyond the “non-canonical” or “inverse” agreement patterns described in previous work on copula constructions (e.g., Béjar and Kahnemuyipour 2017 and works cited there). We present experimental evidence to support this generalization, and then develop an account that unifies it with hierarchy phenomena in other languages, with a focus on PCC effects. Specifically, we propose that what German copula constructions have in common with PCC environments is that there are multiple accessible DPs in the domain of a single agreement probe, the lower of which is more featurally specified than the higher (see, e.g., Béjar and Rezac 2003, 2009; Anagnostopoulou 2005; Nevins 2007). We also offer an explanation as to why number effects are present in German copula constructions but notably absent in PCC effects. We then place our account within the broader context of constraints on predication structures.

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Frequent coauthors

• Rajesh Bhatt

  5 shared

• Gereon Müller

  Leipzig University

  3 shared

• Jessica Coon

  McGill University

  3 shared

• Michael Wagner

  Medical University of Vienna

  2 shared

• E. G. C. Poole

  University of California, Los Angeles

  2 shared

• Bhamati Dash

  University of Southern California

  2 shared

• Kiyomi Kusumoto

  1 shared

• Uri Strauss

  1 shared

Education

• Ph.D., Linguistics

  University of Massachusetts Amherst

  2016

• M.A., Linguistics

  University of Massachusetts Amherst

• B.A., Linguistics

  University of Massachusetts Amherst

• M.A., Linguistics

  University of Leipzig

• B.A., Linguistics

  University of Leipzig