Commas are confusing because they are used in many ways. However, the basic principle to using commas is simple: Use commas to separate clauses and phrases within sentences that have their own meaning.
The “rules” for commas below are broadly, but not universally, accepted. However, a careful writer considers two central issues:
- Reader understanding and
The comma guidelines below will help readers understand your message in many cases. However, even if they are not necessary to improve reader understanding, follow them for consistency. Consistency is a characteristic of professional technical writing.
The commas help the reader find each unique item (or group of items) in a series by separating them.
Example: School officials are dismayed by poor grades, low attendance, and high drug use.
2. Joining Sentences
You can join two complete sentences with coordinating conjunctions. (The entire set of coordinating conjunctions is for, and, nor, but, or, yet, and so. Together, these create the acronym FANBOYS.) The comma lets the reader know when one point is complete and the next will begin. This comma use only applies when you have complete sentences on either side of the conjunction.
Example: The screen inverter stopped working, and the motherboard began to smoke.
3. Introductory Descriptions
An introductory description is before the subject and describes the main verb in some way, such as when, where, how, and why. The comma at the end of the description signals the reader that the main point of the sentence is about to begin. For consistency, do this with even short introductory descriptions. In the following example, the introductory description is underlined.
Example: Following the symposium, participants collaborated on projects. Continue reading