A declarative is a type of sentence that makes a statement or expresses an opinion. It provides information and can be either true or false. For example, "The sky is blue" is a declarative sentence because it states a fact about the sky. Declaratives are commonly used in everyday communication to convey clear messages. In English grammar, declaratives typically follow a subject-verb-object structure. They can be simple, like "She runs," or more complex, such as "The cat chased the mouse across the yard." Understanding declaratives is essential for effective writing and speaking, as they form the foundation of most sentences.