Indefinite articles in Croatian grammar are used to indicate that a noun is not referring to a specific instance of that noun. In Croatian, indefinite articles are actually expressed through the noun itself, by using a non-prefixed form. For example, “a dog” in Croatian would be “pas,” without any article in front of it. This can make learning Croatian grammar a bit more challenging for English speakers, as there are no additional words or prefixes to help identify indefinite articles. However, with practice and understanding of Croatian noun forms, the use of indefinite articles can become more natural.