Case grammar is a system of linguistic analysis, focusing on the link between the valence, or number of subjects, objects, etc., of a verb and the grammatical context it requires.
This theory analyzes the surface syntactic structure of sentences by studying the combination of deep cases (i.e. semantic roles, such as Agent, Object, Benefactor, Location or Instrument etc.)
For instance, the verb "give" in English requires an Agent (A) and Object (O), and a Beneficiary (B); e.g. "Jones (A) gave money (O) to the school (B).
Thus, a case frame describes important aspects of semantic valency of verbs, adjectives and nouns.
Walter A. Cook, SJ, a linguistics professor at Georgetown University, was one of the foremost case grammar theoreticians following Fillmore's original work.