Five Uses of the Comma
“Five Uses of the Comma” is licensed under CC BY-NC-SA by Susan Wood.
“Let’s eat Grandpa” is licensed under CC-BY 2.0 by Brett Jordan
#1. Use a comma to separate items in a series
Example: Joe, Layla, and Mia went to school.
Example: Our favorite foods are pizza, sushi, Costco hot dogs, and ice cream.
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This album is dedicated to my parents, Beyonce, and Jay Z.
This album is dedicated to my parents, Beyonce and Jay Z.
Why is the 2nd sentence incorrect? When the comma after Beyonce is omitted, the last two items can be read as if they are a single unit. In this case, the second sentence is saying that the parents of the person writing the dedication are Beyonce and Jay Z.
#2. Use a comma before a coordinating conjunction joining two or more independent clauses.
Example: The dog ran through a puddle, and he got his paws all dirty.
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The child ate her dinner, and then she asked her mom for more.
The child ate her dinner, and then asked her mom for more.
Why is the 2nd sentence incorrect? There should be no comma in the second sentence because and does not separate two independent clauses like it does in the first sentence. In the second sentence, “and then asked her mom for more” is lacking a subject, which makes it a dependent clause.
#3. Use a comma to set off introductory elements.
Example: In an attempt to fix the TV, he hit the side of it.
It is okay to leave the comma out if the introductory element is brief and its absence won’t confuse the reader.
Example: Yesterday we went to the park.
If you are in doubt, use the comma as it won’t be incorrect.
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Until the spring, course offerings won’t be published.
Until the spring course offerings won’t be published.
Why is the 2nd sentence incorrect? There should be a comma in the second sentence after the introductory element because “Until the spring” merges with the next word “course” and may confuse the reader. A reader of the second sentence might wonder, “Is it ‘Until the spring’? or is it ‘Until the spring course’?
#4. Use a comma to set off parenthetical elements.
Example: That explanation, as I have already said, is not very clear.
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The lawyers, who have an office downtown, think we have no chance of winning.
The lawyers who have an office downtown think we have no chance of winning.�
Why is the 2nd sentence incorrect? There should be commas around “who have an office downtown” in the second sentence since the location of the office is not essential to the meaning of the sentence. It is extra information that the reader does not need to know because the main point of the sentence is that the lawyers think we have no chance of winning.
#5. Use commas to set off quoted elements.
Example: “Please cut the grass,” mom said, “before the rain comes.”
Example: Wasn’t it Charles Dickens who wrote, “It was the best of times, it was the worst of times”?
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“The question,” the teacher said, “is often more important than the answer.”
“The question”, the teacher said, “is often more important than the answer”.
Why is the 2nd sentence incorrect? Commas and periods always go inside the quotation marks.