Assessments of the quality of parts of syntactic grammars of natural languages are useful for the validation of their construction. We extended a grammar of French determiners that takes the form of a recursive transition network and evaluated its quality. The result of the application of this local grammar gives deeper syntactic information than chunking or information available in treebanks. We performed the evaluation by comparison with a corpus independently annotated with information on determiners. We obtained 85 % precision and 93 % recall on text not tagged for parts of speech.