Case Construction is a method used in grammar to indicate the relationship between words in a sentence. It helps clarify the roles of nouns and pronouns, such as who is doing the action or receiving it. Different languages have various case systems, with some using specific endings or prepositions to show these relationships. In English, the most common cases are nominative, accusative, and genitive. The nominative case is used for the subject of a sentence, the accusative for the direct object, and the genitive indicates possession. Understanding case construction is essential for proper sentence structure and meaning.