A punctuation mark used to indicate a pause between parts of a sentence or to separate items in a list.

A comma should be used before a conjunction (like 'and', 'but', 'or') when it connects two independent clauses.

A group of words that can stand alone as a sentence, containing a subject and a verb.

A group of words that cannot stand alone as a sentence and usually begins with a subordinating conjunction (like 'because', 'since', 'although').

A sentence that contains at least two independent clauses joined by a conjunction.

A sentence that contains one independent clause and at least one dependent clause.

Use a comma before the conjunction that connects the two independent clauses.