Recent work in lexical resource construction has recognized the importance of contextualizing the knowledge in existing resources and ontologies with information derived from text corpora. This paper describes the integration of a corpus-based lexical acquisition process with a large, linguistically motivated lexical ontology. This semi-automatic bootstrapping process is used to produce refinements, additions, and modifications to the type specifications for the arguments to predicates in this ontology. In addition, the procedure is used to verify and modify the lexical extensions of the entity types in the ontology.