What do we call a sentence that lacks either a subject or a predicate?

A sentence that lacks either a subject or a predicate is referred to as a sentence fragment. These incomplete sentences do not express a complete thought, which is essential for a sentence to be considered complete. For example, if a sentence says "The dog barking," it has a subject but is missing a predicate that completes the thought, making it a fragment.

Understanding sentence fragments is important for writing clear and effective sentences. Recognizing them helps writers to revise and combine thoughts to enhance clarity, ensuring that each part of their writing accurately conveys the intended message. In contrast, complete sentences include both a subject and a predicate, while run-on sentences consist of two or more independent clauses incorrectly joined. Simple sentences express a complete thought with only one independent clause.