Commas (,) are used in written language and reflect one of the following: the signaling of a separate idea (example: The movie was, in my opinion, wonderful!) a listing of similar items grouped together (example: red, orange, yellow and green) separates the day of the month from the year (example: June 15, 2014) separates a city from a state (example: Los Angeles, California) the end of a greeting or closing in a letter (example: Dear John, and Truly yours,)   When listing only two items, no comma is needed. Example: John and Mark. However, when listing three or more items in a row, a... Show more

Commas (,) are used in written language and reflect one of the following:

the signaling of a separate idea (example: The movie was, in my opinion, wonderful!)

a listing of similar items grouped together (example: red, orange, yellow and green)

separates the day of the month from the year (example: June 15, 2014)

separates a city from a state (example: Los Angeles, California)

the end of a greeting or closing in a letter (example: Dear John, and Truly yours,)

 

When listing only two items, no comma is needed. Example: John and Mark.

However, when listing three or more items in a row, a comma is used to separate the listed items: Example: boats, trains, planes and cars are all modes of transportation. [NOTE: A comma appears before words of conjunctions such as and, but, or, nor, so and yet.] If that is the case, then why is there no comma in our above example between “planes and cars?”

The general rule is that if you are listing a series of items a comma does not appear between the next to last and last item. The word “and” here replaces the need for a comma. However, when you are linking two sentences together (known as a compound sentence), the comma is used to show the end of one sentence and the beginning of the next sentence such as in the example: “She studied mathematics, and she also studied foreign languages.”

Show less