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English Composition 2

Four Comma Rules

This page explains four rules for comma usage that should help you use commas correctly. There are many rules for comma usage, but if you remember just these four rules, you should be on your way toward becoming a master of the comma.

  

1. The FAN BOYS" Rule

If you have two independent clauses (basically complete sentences) separated from one another with a coordinating conjunction, then you should use a comma in front of the conjunction. You can easily remember the coordinating conjunctions if you remember the words "FAN BOYS." Together, the first letter of each of the conjunctions spells "FAN BOYS." The coordinating conjunctions are for, and, nor, but, or, yet, so. A complete sentence followed by one of these words and another complete sentence means that you should put a comma in front of the conjunction.

• George's wife unsuccessfully searches for the cat, and she then returns to the hotel room. (correct)
• George's wife unsuccessfully searches for the cat and then returns to the hotel room. (correct--there is not an independent clause after the conjunction, so no comma)


• George's wife says that she wants her own table, and she says that she wants a different hairstyle. (correct)
• George's wife says that she wants her own table and that she wants a different hairstyle. (correct--there is not an independent clause after the conjunction, so no comma)

Remembering and applying the "FAN BOYS" rule can go far in helping you use commas correctly.

2. Restrictive and Nonrestrictive Clauses

Clauses often begin with "who" or "which." If the "who" or "which" clause identifies (or restricts) which ones you are talking about, then you do not use commas. If the "who" or "which" clause is just giving extra information and is not identifying or restricting which ones you are talking about, then you should put commas around the phrase.   

• Women who believe abortions should remain legal recently held a rally in Washington, D.C. (correct--because the "who" phrase is identifying which type of women we are talking about)
• Women, who believe abortions should remain legal, recently held a rally in Washington, D.C. (incorrect--with the commas, we are saying that all women believe abortions should remain legal)


• Students who do not devote enough time to their studies do not succeed in college. (correct--because the "who" phrase is identifying which type of students we are talking about)
• Students, who do not devote enough time to their studies, do not succeed in college. (incorrect--with the commas, we are saying that all students do not devote enough time to their studies)
   
• My dad who fought in World War II used to tell me stories about his adventures. (incorrect--without the commas, you are indicating that the "who" clause is identifying which "dad" you are referring to, but you can have only one dad)
• My dad, who fought in World War II, used to tell me stories about his adventures. (correct--the "who" phrase is not identifying which "dad" you are referring to, so you need the commas)

3. Appositives

An "appositive" is an exact renaming. When you present an appositive (in other words, when you repeat something but use a different name for it), then you put commas around the appositive. 

• Ralph Ripley's first novel, Under the Pine Tree, was a bestseller. (correct)
• Ralph Ripley's novel In the Coconut Grove is my favorite novel written by this genius. (correct--no commas here because the sentence makes clear that Ripley wrote more than one novel. In the Coconut Grove is the title of one of his novels, but it is not the exact same thing as his "novel" because he wrote more than one novel. The title of the novel does not give us an exact renaming in this sentence, so we do not use commas. Here, the title is being used as a restrictive clause.)

4. Commas with Complex Sentences

A complex sentence is made up of an independent clause and one or more dependent clauses. An independent clause can stand alone as a complete sentence; a dependent clause cannot stand alone as a complete sentence. 

Dependent clauses--the ones that cannot stand alone as complete sentences--begin with words called "subordinating conjunctions." Below are some of the most common subordinating conjunctions:

• after
• although
• as
• because
• before
• even though
• if
• since
• though
• unless
• until
• when
• whenever
• whereas
• wherever
• while

If the dependent clause appears before the independent clause, then a comma is used to separate the two clauses, as in the following:

1. Because Mary and Samantha arrived at the bus station before noon, I did not see them at the station.
2. While he waited at the train station, Joe realized that the train was late.
3. After they left on the bus, Mary and Samantha realized that Joe was waiting at the train station.

If the dependent clause appears after the independent clause, then a comma is not used to separate the two clauses, as in the following:

1. I did not see them at the station because Mary and Samantha arrived at the bus station before noon.
2. Joe realized that the train was late while he waited at the train station.
3. Mary and Samantha realized that Joe was waiting at the train station after they left on the bus.

The dependent clauses in the sentences above are italicized. Notice how the two sets of sentences above are identical except for the order of the dependent and independent clauses in the sentences: this order determines the comma usage.

Try this One

In some cases, comma usage can make a big difference in the meaning that you convey. Applying the rules for appositives, restrictive clauses, and nonrestrictive clauses, see if you can tell the difference in meaning between the two sentences below:

• My friend Ralph is coming to dinner.
• My friend, Ralph, is coming to dinner.

There is a big difference in meaning here! And we have to feel sorry for the writer of the second sentence above.