Guidelines for Using Commas
WHEN DO YOU USE A COMMA?

Do you feel comfortable knowing where to place a comma when you write? When asked this question, many people say they are never sure. Some people have been taught to use a comma whenever they pause, especially when they would pause in speaking. Since many people pause to breathe or to swallow, pausing is not a reliable reason for using a comma. Instead, follow this general rule for using a comma: Use a comma to guide the reader through the sentence and to prevent misreading.

FOLLOW THESE FIVE COMMA GUIDELINES.

  1. Use a comma to guide the reader when you join sentences with the "FANBOYS."
         Use a comma when you use the FANBOYS (for, and, nor, but, or, yet, and so) to join two sentences. The comma signals the reader just like a warning sign on a highway that the direction of the sentence is about to change. Instead of thinking that "and" or "but" are joining two words, the reader should see the comma as a sign that "and" or "but" is going to join a new complete idea that is related to the first idea. (FANBOYS is an acronym. The actual term for the words is coordinate conjunctions. When the two sentences are joined with coordinate conjunctions, they are known as independent clauses.)

    • Be sure to leave some money in your savings account, for next month the auto insurance is due. Note: If you forget to put the comma before "for," the reader may read "for next month" with the first part of the sentence instead of the second part.
    • Life is full of many surprises, and many of these surprises are wonderful.
    • Breakfast is an important meal, but what you eat for breakfast is also important.
    • I am going to travel in California in January, so the next time you will see me will be later in February.

    Caution:
    • Do not use a comma when you join only two words or two phrases with "and," "but," or "or": I like bacon and eggs.
    • Do not use a comma when you use "for" as a preposition to join a phrase to the rest of the sentence: Save some money for a rainy day.
    • Do not use a comma when you use "so" to emphasize another word: I am so tired. "So" is also used along with "that" to join words in a sentence. When you use "so that" to join groups of words in a sentence, do not use a comma: I like to eat breakfast early so that I will have plenty of energy at work. Sometimes you can eliminate "that," but still do not use a comma: I like to eat breakfast early so I will have plenty of energy at work.

  2. Use a comma to guide the reader when you introduce the main part of the sentence with a transitional word, a transitional phrase, or a clause.

    1. Transitional word: First, do no harm.

    2. Transitional phrase: Just before daylight, we will break camp and start our climb up the mountain.

    3. Introductory clause: When the sun is still fairly high in the sky, we will have to start our climb down the mountain to reach the campsite before dark.

    Note: When a subordinate clause begins a sentence, use a comma at the end of a subordinate clause but not when the subordinate clause ends the sentence. Notice that the preceding sentence illustrates the rule: The sentence both begins and ends with a subordinate clause. The first introductory clause ends with a comma when the main clause begins the last part of the sentence. The sentence also ends with a subordinate clause, but that clause is not preceded by a comma because it flows logically out of the first part of the sentence. Other typical subordinate conjunctions besides when are if, since, because, even though, although, and so that.

  3. Use a comma to guide the reader when you list items in a series: You can use list a series of words, phrases, or even sentences.

    1. Series of words: I like to eat cereal, fruit, juice, and toast for breakfast

    2. Series of phrases: I like to exercise early in the morning, eat a leisurely breakfast, and finally show up for work. I hope there is still someone willing to pay a lazy person like me.

  4. Use a comma to guide the reader when you interrupt the flow of the sentence with a transitional word or phrase or when you add extra information for emphasis:

    1. Transitional word: Be sure to put some money in your savings account every month, however, if you want to have money set aside for an emergency.

    2. Transitional phrase: If you put only five dollars in your saving account every month, for example, you will have saved hundreds of dollars in just a few years.

    3. Extra information added for emphasis: Life is full of many surprises, sometimes too many, even though some of these surprises are wonderful.

    4. Extra information added for emphasis: Pat your skin dry with a soft, clean towel, leaving the face slightly damp. [Notice that "leaving the face slightly damp" is a condensed version of an independent clause: "This process leaves the face slightly damp."]

    Note: Use the comma when the phrase ends the sentence as an afterthought rather than an interruption in the middle of the sentence:

    • Be sure to put some money in your savings account every month, even five dollars.

    • Life is full of many surprises, sometimes too many.

    • Caution: The phrase "such as" is used to connect a term to an example of that term. If "such as" appears directly between the term and the example, then you would not use a comma, but if words interrupt the term and the example, then you would use a comma:
      • Be sure to include vegetables such as broccoli and carrots in your diet.
      • Be sure to include vegetables in your diet, such as broccoli and carrots.

  5. Use a comma to guide the reader whenever you use quotations marks, dates, and addresses:

    1. When you lead into a quotation with a subject and verb, use a comma before the quotation, as shown below:

      • He said, "Are you going to stay at home this week-end?"
      • Did she say, "I am going to stay at home this week-end"?

      Notice that the question mark may be placed either inside or outside, depending upon the meaning of the sentence. The first sentence above is actually a statement that a person asked a question. Only the words in quotation marks are a question. The second sentence is a question, but the words inside the quotation marks are a statement, so the question mark is placed outside the quotation marks to correspond to the question that precedes the quotation.

    2. Use a comma after the day and after the year when the complete month, day, and year are written inside a sentence:
      • I was born on October 31, 1946, in North Carolina.

    3. Use a comma around the parts of an address when the address appears inside a sentence:
      • I was born on October 31, 1946, in Pinehurst, North Carolina, in what was then known as Moore County Hospital (now FirstHealth Moore Regional Hospital).

      Notice in this example that when a parenthetical remark that is not a complete sentence is used at the end of a sentence, the period is placed after the closing parenthesis. If the parenthetical remark had been a complete sentence, it would be placed after the sentence with a period inside the closing parenthesis:
      • I was born on October 31, 1946, in Pinehurst, North Carolina, in what was then known as Moore County Hospital. (That name of that hospital in 2001 is FirstHealth Moore Regional Hospital.)

    4. It is customary in the United States to place either a comma or period within the closing quotation marks:

      • John said, "I am going to stay at home this week-end," but then he changed his mind.
      • John said, "I am going to stay at home this week-end."

    5. Although these rules apply to comma use, if you are writing a longer sentence to introduce a quotation, you may use a colon instead of a comma to introduce the quotation.
      • President Franklin Roosevelt inspired many Americans with this statement: "The only thing we have to fear is fear itself."

      Colons and semi-colons, by the way, are always placed outside quotation marks:
      • "Live long and prosper": Are these words from Mr. Spock of Star Trek?

  6. More Comma Advice
    If you would like more advice on using commas, please click here. Note: This site will open in a new window.