Asset Publisher Asset Publisher

A Processing-friendly Grammatical Model for Parsing and predicting on-line Complexity

Beginning date : 2018

End Date : 2021


Short description

While psycholinguistic studies show that sentence processing goes incrementally "from left to right" (i.e. sequentially with respect to how words are produced and perceived, Bever 1970, Fodor 1978, De Vincenzi 1990, MacDonald et al. 1994, a.o.), the prevailing models of theoretical syntax are often indifferent (Pollard and Sag 1994) or even in conflict (Chomsky 1995) with this assumption of incrementality and lexical items processing order. A serious attempt to fill this interdisciplinary gap was started by Phillips (1996) that reshaped the basic phrase structure building operations so as to allow incremental constructions of syntactic constituents from left to right; in addition, the implementation of Parsing algorithms (Kobele 2012) and complex NLP systems (e.g. a machine translation system from verbal Italian to Italian Sign Language, Chesi et al., 2008, Geraci & Chesi 2009) has been possible only by virtue of fully formalized, and easily upgradable, minimalist grammars support (Stabler 1997, Chesi 2004, 2012).


On the one hand, from a formal point of view, this approach showed that sequential processing ("left-right") is empirically advantageous (Phillips 2002), on the other, that the orientation of the syntactic derivation should be logically re-orientated top-down (especially in terms of lexical insertion and Filler-Gap dependency, Fodor 1978) (Chesi 2004-2012). This plainly allowed to explain a number of otherwise intricate empirical data, traditionally investigated by theoretical approaches (parasitic gap constructions, quantifiers scope, restrictions on filler-gap dependencies and rightward movement, cf. Bianchi & Chesi 2006, 2008, 2012, Chesi 2013 respectively) and also experimental data (results of self-paced reading, eye-tracking and neuroimaging experiments, cf. Mancini et al. 2013, on filler-gap dependencies, Sprout et al. 2013). Recently, the simplification of the basic grammatical operations (Chomsky 2005) reduced the complexity of the theory and increased its explanatory power, raising fundamental questions about the neurophysiology of language and the acquisition and processing of grammatical rules (Moro et al. 2001, Hood, 2011), although it did not completely solve this tension.

On the other hand, in terms of Natural Language Processing, it has been shown that the explicit formalization of linguistic competence allows us to implement more efficient Parsers, where purely statistical models productively integrate syntactic restrictions (Collins 1999).

 At present, therefore, the integration of formal-linguistic models with neuro/psycho-linguistic and computational ones becomes a priority.

The urgency of investigating this (that is the main goal of this project) is demonstrated by the main topic of the recent 25th Annual CUNY Conference on Human Sentence Processing, organized by J. Fodor (New York, 14-16/03/2012, Sponsor: National Science Foundation): discussing more promising models of Linguistic Competence and (psycholinguistic/computational) Performance. At this conference, Chesi was Invited Speaker (presenting the formalism discussed in this project), together with N. Chomsky, S. Fong, L. Frazier, C. Phillips, I. Sag and M. Steedman (




The goal of the project is to define precise complexity metrics, coherent with a formal grammatical model that is cognitively plausible.

The project will consist of three basic work-packages:

Formal Linguistics - the formal model will be refined in order to provide explanatory support for the experimental data that will be collected (see 2.); this model will be the skeleton of the parsing and generation algorithm that will be further developed (see 3.)

Experimental Linguistics - experimental data set will be enriched; new data will be collected through off-line grammaticality judgments (magnitude estimation via Osucre software, cf. Bianchi & Chesi 2012; elicited production, cf. Belletti & Chesi 2011) and on-line (eye tracking and self-paced reading, cf. Traxler et al., 2002, Phillips et al. 2012);

Computational Linguistics - Italian parsing software, already prototyped in Chesi (2004), will be updated. Also an interactive simulator generating sentences using the top-down algorithm that will emerge by integrating experimental data with the refined formal model will be realized.

Partial and final results will be made available on the web platform which currently includes the major publications related to this research stream on "Top-Down Left-Right Grammars" (


Involved persons

PI: Prof. Cristiano Chesi

Other IUSS members: Ph.D. Pauli Brattico, Prof. Andrea Moro

External collaborator: Prof. Valentina Bianchi (University of Siena)


CISCL, Interdepartmental Center for Cognitive Studies of Language (University of Siena)



Chesi C., P. Canal (2019) Person Features and Lexical Restrictions in Italian Clefts. Frontiers in Psychology. 

Topciu K., C. Chesi (2019) Reflexives, Impersonals and Their Kin: a Classification Problem.. Proceedings of the Sixth Italian Conference on Computational Linguistics (CLiC-it 2019). In CEUR WORKSHOP PROCEEDINGS - ISSN:1613-0073 

Brattico P., C. Chesi (2019) A top-down, parser-friendly approach to pied-piping and operator movement. Lingua.

Chesi C., P. Brattico (2018) Larger than expected: constraints on pied-piping across languages . Rivista di Grammatica Generativa, RGG 2018.04. 1-38 

Chesi C., A. Moro (2018) Il divario (apparente) tra gerarchia e tempo. Sistemi intelligenti, XXX, n. 1, aprile 2018: 11-32 doi: 10.1422/89315

Chesi C., P. Canal (2017) Feature Retrieval Cost and on-line/off-line complexity in clefts. Proceedings of AMLAP, Architectures and Mechanisms of Language Processing. Lancaster, September 7-9 2017

Chesi C. (2017) A perfect (machine) language. Abstract proceedings of AISC 2017

Chesi C. (2017) Phase-based Minimalist Parsing and complexity in non-local dependencies. Proceedings of CLiC-it 2017. CEUR WORKSHOP PROCEEDINGS, ROMA:CEUR Workshop Proceedings, ISBN: 9788899982768, ISSN: 1613-0073, Rome, 11-13 December 2017, doi: urn:nbn:de:0074-2006-4

Chesi C., A. Moro (2016) Mind the gap between hierarchy and time. AISC : Associazione Italiana di Scienze Cognitive, “Mind the Gap: Brain, Cognition and Society - 13th Annual Conference of the Italian Association for Cognitive Sciences”,, accessed 12 dicembre 2016,

Chesi C. (2015) On directionality of phrase structure building. Journal of Psycholinguistic Research. 44(1): 1-50 - DOI: 10.1007/s10936-014-9330-6

Chesi C. (2015) Real-time processing of complex sentences (presentation of the Feature Retrieval Cost - FRC). slides talk at Scula Normale Superiore

Chesi C. (2015) Il processamento in tempo reale delle frasi complesse. Proceedings of “Compter Parler Soigner” (pp.21-38), E.M Ponti e M. Budassi (eds.). Pavia: Pavia University Press

Chesi C., A. Moro (2015) The subtle dependency between Competence and Performance. in Á. J. Gallego and D. Ott (eds.) "50 Years Later: Reflections on Chomsky’s Aspects". MIT Working Papers in Linguistics, 77:33-46

Chesi C., A. Moro (2014) Computational complexity in the brain. In: Newmeyer FJ, Preston LB, eds. Measuring grammatical complexity, Oxford: Oxford University Press. pp. 264–280.

Bianchi V., C. Chesi (2014) Subject islands, reconstruction, and the flow of the computation. Linguistic Inquiry 45(4):525–569 - DOI: 10.1162/ling_a_00166

Chesi C. (2014) La computazione linguistica. in Lazzari (2014) Informatica Umanistica (II edizione). McGraw Hill

Bianchi V., C. Chesi (2014) On a PP/DP asymmetry in extraction. in Structures, Strategies and Beyond, Edition: Linguistik Atuell Series, Publisher: John Benjamins, Editors: Elisa Di Domenico, Cornelia Hamann, Simona Matteini

Chesi C. (2014) What memory retrieval tells us about intervention effects. R. Zamparelli (ed.) 40th Incontro di Grammatica Generativa (Generative Grammar Meeting. Book of abstracts. pp. 50-51

Chesi C., A. Moro (2013) Hierarchy and recursion in the brain. GLOW Newsletter n.70 pp.54-55 ISSN: 0924-8749

Chesi C. (2013) Do the 'right' move. Studies in Linguistics. Vol. 6, Special issue on 'directionality of phrase structure building'. ISSN: 2281-3128.

Chesi C. (2013) Introduction to directionality. Studies in Linguistics. Vol. 6, Special issue on 'directionality of phrase structure building'. ISSN: 2281-3128.

Chesi C. (2012) Rightward movement from a top-down perspective. in Rightward Movement in a Comparative Perspective, Amsterdam: John Benjamins, Ed. G. Webelhuth, M. Sailer, H. Walker pp.243-280 ISBN: 9789027255839

Chesi C. (2012) Competenza e performance: una distinzione cognitivamente obsoleta. Sistemi Intelligenti A. XXIV, n. 2:243-260 ISSN: 1120-9550