Clauses

A clause is a grammatical unit that contains a subject and a predicate. It may form a full sentence by itself (an independent or main clause) or function as part of a larger sentence (a dependent or subordinate clause). The distinction between clauses and phrases hinges on the presence of a finite verb with a subject.

Independent clauses express a complete thought and can stand alone: “The cat slept.” Dependent clauses rely on an independent clause to provide a complete meaning and are introduced by subordinating conjunctions such as because, since, although, or by relative or interrogative words. Subtypes include relative clauses (which modify a noun), noun clauses (that she left is uncertain; acting as a noun), and adverbial clauses (time, place, cause, condition).

Two or more independent clauses can be joined to form compound sentences with coordinating conjunctions (for, and, nor, but, or, yet, so) or with a semicolon. A dependent clause at the start of a sentence is typically followed by a comma; when it comes after, the comma may be optional.

In law, a clause is a provision in a contract or statute, such as a confidentiality clause or a termination clause. In computing, SQL employs clauses such as WHERE and ORDER BY to constrain or sort data.