What grammatical term names a clause that contains a subject and verb and can stand alone as a sentence?

A clause containing a subject and verb that can stand alone as a sentence is an independent clause.

An independent clause expresses a complete thought and is also called a main clause. For example, “The rain stopped” contains a subject, “rain,” and a predicate built around the verb “stopped”; it can function as a complete sentence by itself.

Independent clauses can appear alone or combine with other clauses. Two independent clauses may be joined with a semicolon or with a comma and a coordinating conjunction such as “and,” “but,” “or,” “so,” or “yet.” Joining them incorrectly with only a comma creates a comma splice.

The main contrast is a dependent, or subordinate, clause. A dependent clause may contain its own subject and verb but cannot stand alone because it begins with a subordinating word or otherwise leaves the thought incomplete—for example, “because the rain stopped.” A relative clause is another type of dependent clause, while a prepositional phrase is not a clause because it lacks a subject–verb structure.