Noun cases in Croatian grammar are an essential aspect of the language. In Croatian, there are seven cases: nominative, genitive, dative, accusative, vocative, locative, and instrumental. These cases affect the form of a noun, pronoun, or adjective and demonstrate the function it has within a sentence. Mastering the use of these cases is crucial for communicating effectively in Croatian, as they play a significant role in conveying meaning and ensuring proper sentence structure.