Page web de Benoît Sagot  —  équipe Alpage (INRIA / Paris 7)

The Lefff (Lexique des Formes Fléchies du Français / Lexicon of French inflected forms) is a large-scale morphological and syntactic lexicon for French, distributed under the LGPL-LR free software license (Lesser General Public License For Linguistic Resources).

Main reference: Sagot (2010). The Lefff, a freely available and large-coverage morphological and syntactic lexicon for French. In Proceedings of the 7th international conference on Language Resources and Evaluation (LREC 2010), Istanbul, Turkey

The Lefff is developed within the Alexina architecture (Architecture pour les LEXiques INformatiques et leur Acquisition / Architecture for digital lexica and their acquisition), in parallel with other lexicons that use the same format (in particular the Leffe, for Spanish). This architecture consists of two levels:
  • the intensional lexicon, which describes for each entry its lemma (canonical form + inflection table) as well as deep syntax information (deep sub-categorization frame + possible realizations + possible restructurations)
  • the extensional lexicon, built automatically by compilation of the intensional lexicon; this generation process includes an inflection step, depending on the inflection class associated with the intensional entry, then step for constructing the different syntactic structures (one for each relevant restructuration) associated with each inflected form (syntactic information may vary from one form to another, in particular for infinitive and participe forms, and from one restructuration to another).
Lexical information included in the Lefff originate in different works:
  • automatic acquisition (with manual validation) thanks to statistical techniques applied on raw corpora (Clément, Sagot and Lang 2004, Sagot 2005),
  • automatic acquisition (with manual validation) of specific syntactic information (Sagot 2006 (PhD dissertation), ch 7)
  • manual correction and extension guided by automatic techniques, such as error mining in parsing results (Sagot and de La Clergerie, 2006),
  • comparaison with other ressources, and in particular with Lexicon-Grammar Tables: impersonnal constructions, adverbs in -ment, several classes of frozen verbal expressions (Sagot and Danlos 2006, Danlos and Sagot 2007, Sagot and Danlos 2007, Sagot and Fort 2007) ; moreover, a certain amount of nominal and adjectival entries have their origin in the Multext morphological lexicon for French (Véronis 1998).


Latest release (3.4)
Old versions can be downloaded on the "files" page of the Alexina project.