A computational implementation of periphrastic verb constructions in French

Abstract

This paper describes the treatment of passive and compound past tense in FrGramm, a computational grammar of French, implemented within Lexical-Functional Grammar (LFG) using the XLE software. Due to the dual auxiliary system and past participle agreement, the latter periphrasis manifests greater structural complexity and therefore presents a greater challenge to computational implementation in French than in languages such as English and Portuguese. An additional difficulty is modeling the morphological and syntactico- semantic regularities of the passive construction. In FrGramm, this problem is solved by means of a productive lexical rule. FrGramm also implements the constraints governing the building of both verbal periphrases, excepting participle object agreement. The implementation was evaluated by applying a parser to a set of 157 grammatical sentences and a set of 279 ungrammatical sentences. All sentences from the former set were correctly parsed. Only two constructions from the latter set that violate the linear precedence of the compound past auxiliary over the passive auxiliary were analyzed as grammatical. FrGramm is the only LFG grammar of French with similar coverage that is freely available on-line. A future version will handle participle object agreement and also avoid the mentioned overgeneration.