What is it called when two or more subjects are joined together by "and" or "or" that share a common verb?

The correct term for two or more subjects joined together by "and" or "or" that share a common verb is called a compound subject. A compound subject occurs when multiple nouns or pronouns are connected by coordinating conjunctions, allowing them to function together within the same sentence, taking a single verb. For instance, in the sentence "The cat and the dog are playing," both "the cat" and "the dog" make up the compound subject and share the verb "are playing." This structure is essential for clarity and fluency in sentence construction, as it allows the sentence to convey that both subjects are involved in the action simultaneously.