APA Fact of the Week: Correct Comma Usage

Correct comma use is essential to the clarity of a dissertation. Commas are used to separate units of meaning, such as phrases and clauses, and support the cadence of the sentence. Therefore, please recognize the proper uses of the comma in different situations. Below are a few examples of correct comma use. For more information, please look in the APA Manual (APA6, pp. 88–89).

Examples:

Use commas

• between elements (including before and and or) in a series of three or more items
  • in height, width, and depth
  • in a study by Stacy, Newcomb, and Bentler (1991)
• to set off a nonessential or nonrestrictive clause
  • Switch A, which was on the panel, controlled the recording device
• to separate two independent clauses joined by a conjunction
  • Cedar shavings covered the floor, and paper was available for shredding and nest building

Do not use commas

• before an essential or restrictive clause
  • The switch that stops the recording device also controls the light
• between the two parts of a compound predicate
  • All subjects completed the first phase of the experiment and returned the following week for Phase 2