1. Case refers to the grammatical relationship between words in a sentence. It shows how nouns and pronouns are related to verbs and other parts of a sentence.
2. Languages like Latin and Pitta-Pitta have complex case systems with suffixes that mark nominative, ergative, accusative, dative, and other cases. English has lost most of its case system but retains some forms like possessive 's.
3. A case grammar approach emphasizes the semantic relationships indicated by verbs and how nouns are related through agentive, benefactive, comitative, and dative cases.