Coordinating conjunctions are joining words that connect words or groups of words, including independent clauses, of equal grammatical rank. The following coordinating conjunctions: for, and, nor, but, or, yet, so, sometimes called fanboys, require the use of a comma to connect two independent clauses.

A subordinating conjunction is a word or a group of words that introduces a subordinate clause and indicates a relationship between the idea in the independent clause and the idea in the dependent clause.

Note that some of these words may also appear in the list of prepositions.

Examples

When after and before are followed by a noun phrase, they function as prepositions. When they introduce subordinate clauses, they function as subordinating conjunctions.