A declarative is a type of sentence that makes a statement or expresses an idea. 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 thoughts clearly. In English grammar, declarative sentences typically begin with a subject followed by a verb. They can be simple, like "Dogs bark," or more complex, such as "The cat sat on the mat while the dog watched." Understanding declaratives is essential for effective writing and speaking.