Punctuation—Commas
and Semicolons
When we speak, we pause for emphasis or to catch our breath. In written sentences, commas show these pauses. Commas also work like road signs to guide readers to the message that we want to convey. The textbook gives us many comma rules, too many to remember. Some of them simply state specialized cases of other rules. If you learn the basics, everything else will fall into place. As always, we strive for clarity so that readers receive the precise message that we send.
1. Place a comma before a conjunction in a compound sentence
Mary went to the store, and she bought some bread.
2. Place a comma after an introductory phrase or clause
When I was in school, I turned in every assignment on time.
If you want to succeed in this class, you must complete all assignments.
Consequently, you will receive a good grade.
Daniel, what are you doing?
3. Use commas to set off parenthetical words, phrases, and clauses (words, phrases, and clauses that you can remove and still have a good sentence)
Martha, my older daughter, teaches math.
She rushed, holding the report in her hand, down the hall to the office.
4. Use commas to separate items in a series.
The college raised fees, reduced maintenance, fired assistant professors, turned down the heat, but went bankrupt anyway.
Mathilda tried on prom dresses of red, blue, and yellow, and green polka dots.
HOT TIP: Grammar rules say that the comma before the conjunction and final item of a series is optional. As you can see in the last example, if we don’t put a comma after yellow, we might have a yellow-and-green-polka-dot dress instead of a yellow dress and a green-polka-dot dress. If you put the comma before the conjunction, you will never be wrong; if you don’t put the comma before the conjunction, readers may misinterpret your writing.
5. Use commas with quotation marks to set off direction quotations from the clause that names the source of the quotation (except when other punctuation is used)
“I’m sorry,” she said, “but all sections of the course are closed.”
“Are you sure?” he asked.
6. Use commas to separate parts of dates, addresses, and numbers
Susie lives at 601 Main Street, Orlando, Florida, and has for ten years.
(Notice the comma after Florida.)
Jody enlisted on April 15, 1983, and began boot camp on April 16.
(Notice the comma after 1983.)
Based on the last census, Orlando has a population of 1, 784, 693.
HOT TIP: Avoid overusing commas. Learn the rules and apply them consistently.
Semicolons are stronger than commas, but not as strong as a period. If you think of road signs, a comma is a Yield sign, and a period is a Stop sign. Consider a semicolon a rolling stop. We use semicolons in two conditions:
1. to join closely related independent clauses
Mary needed bread; she went to the store.
2. to separate items in a series when one or more items contain commas
Several people went to see Cirque du Soleil at Downtown Disney last night: John, my older brother; Adam, a friend; Mary; and I.
Without the semicolons, we wouldn’t know whether my older brother is Adam, John, or a separate person; or whether the friend is Mary, Adam, or another person.
Commas seem to give some people fits, and semicolons seem to intimidate. Learn a few rules and gain control over these punctuation marks. They will make your life easier. . . .