Grammatical Cases

Charles J. Fillmore (born 1929) is an American linguist, and an Emeritus Professor of Linguistics at the University of California, Berkeley.

He was one of the first linguists to introduce a representation of linguistic knowledge that blurred this strong distinction between syntactic and semantic knowledge of a language. He introduced what was termed case structure grammar and this representation subsequently had considerable influence on psychologists as well as computational linguists.

Grammar Case 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. 

The system was created by the American linguist Charles J. Fillmore in (1968), in the context of Transformational Grammar. This theory analyzes the surface syntactic structure of sentences by studying the combination of deep cases (i.e. semantic roles) -- Agent, Object, Benefactor, Location or Instrument -- which are required by a specific verb.

According to Fillmore, each verb selects a certain number of deep cases which form its case frame. Thus, a case frame describes important aspects of semantic valency, of verbs, adjectives and nouns.
Case frames are subject to certain constraints, such as that a deep case can occur only once per sentence. Some of the cases are obligatory and others are optional. Obligatory cases may not be deleted, at the risk of producing ungrammatical sentences.
For example, Mary gave the apples is ungrammatical in this sense.

Grammatical Cases