Use commas to separate coordinate adjectives that modify the same noun:
He had a big, round ball.
She wore a long, ruffled, orange skirt.
NOTE: Coordinate adjectives can be interchanged without creating an
awkward sentence.
Do not separate adjectives that are not coordinate:
The old brick house was demolished.
-NOT-
The old, brick house was demolished.
NOTE: Since "old" and "brick" are not interchangeable in this
sentence they are not coordinate. Thus, the comma separates
them needlessly in the second example.
Comma - Appositives:
Use commas to enclose or separate appositives:
Phil, the big fat guy, squeezed into the
front seat.
NOTE: An appositive is a word or phrase that relabels a preceding noun.
Do not use commas to enclose or separate an appositive that has become part of a proper name:
Jimmy the Greek
Alexander the Great
Comma - Clauses:
Use a comma to separate the parts of a compound sentence when a pause is needed for clarity and/or when the clauses are long:
Good cheese has been produced around
here for years, and I enjoy having fresh cheese
available.
Do not use the comma to separate the parts of a short compound sentence:
The time is now and the need is great.
Do not use a comma to separate two verbs that share the same subject:
He came from way out west and quickly
learned the eastern style.
My boss always arrives early and stays late.
Use commas to enclose or separate a nonrestrictive (nonessential) adjective clause:
His car, which is badly rusted, was stolen
again.
The thief, who apparently likes wrecks,
struck in the middle of the night.
Do not use commas to enclose or separate a restrictive (essential) adjective clause:
A car that is badly rusted and in need of
paint will rarely be stolen.
People who live in glass houses shouldn't
throw stones.
Use a comma after a long introductory prepositional phrase or clause:
By the length of his beard and hair, we could
tell he had been at sea a long time.
Because he lacked both food and water, we
wondered how he had survived so long.
Short introductory prepositional phrases or clauses are usually not separated by a comma:
By midweek we were finished.
On Monday mornings the bank is open early.
When you finish please lock the door and
leave the key under the mat.
Use a comma after introductory participial (verbal) phrases:
Finding nothing but white water between
ourselves and the shore, we argued about
what to do.
Having no other choice, we swam for our
lives.
Use commas to set off nonrestrictive (non–essential) participial phrases:
The Binkly and Hopper comedy team, soon
to arrive in town for a weekend of shows,
is a riot.
Do not use commas to enclose or separate a restrictive (essential) participial phrase:
Everyone planning to stay in town for the
weekend should try to get tickets to one
of the shows.
Use commas to enclose or separate descriptive phrases following the noun they modify:
Big John, strong as an ox, is a dangerous
man.
Normally, a comma is used to separate a dependent clause from the main clause:
Unless telephone numbers are listed in
the directory, they can be very difficult
to find.
No comma is needed if the dependent clause is short, and it is clear where the main clause begins:
When we concentrate we can perform at
our best.
However, if the main clause precedes the dependent clause, a comma is not needed unless the clause is clearly nonrestrictive:
He comes here on Mondays because it
is free spaghetti night.
He always eats at least three plates of
spaghetti, which is a lot of food for a
man of his small size.
Use a comma to set off words, phrases, or clauses if the meaning of the sentence would otherwise be unclear:
Unclear: Underneath her attitude was friendly.
Better: Underneath, her attitude was friendly.
Unclear: Down the walk he came in his shorts
with his shirt tail flapping.
Better: Down the walk he came, in his shorts,
with his shirt tail flapping.
Use a comma to separate identical words in a sequence:
Whatever you do, do it well.
If it be so, so be it.
Comma-Compound Personal Pronouns:
Do not use commas to enclose or separate compound personal pronouns:
Louise herself picked up the tab.
Comma - Contrasting Words or Phrases:
Use commas to enclose or separate contrasting words or phrases:
Listening, not talking, is the way to
learn.
Typing is best performed when the
typist uses all ten digits, not just
two or four.
Comma - Dates:
Use commas to enclose or separate dates:
The wedding was celebrated on March 15, 1989.
Since June 1, 1989, they have been living with the
parents of the groom.
Comma - Exclamations:
Use a comma to set off a light exclamation:
Oh my, that is good news.
Comma - Names, Personal Titles:
Use commas to separate the name of a person addressed from the rest of the sentence:
Quite frankly, Mr. Jones, the offer is
insultingly low.
Whenever you have troubles, Jim, you
should let us know.
Use a comma to separate inverted names in a reference or list:
Jones, John A.
Use commas to enclose or separate a title or degree from the name which it follows:
Phyllis Jenkins, Vice President
Do not use commas to enclose or separate a title or degree from the name which it precedes:
Vice President Phyllis Jenkins
Comma - Numbers:
Use commas to separate large numbers into groups of three digits:
1,593,900,000
Use a comma to separate two consecutive numbers or words indicating numbers:
They had fifteen, one–hundred pound bags.
The rugby club now boasts 2,500, forty–year–old
members.
Comma - Omissions:
Use a comma to denote that a word or phrase has been omitted because it is obvious, or has already been used in the sentence, and need not be repeated for clarity:
Some men prefer blondes, others,
brunettes.
Anne and Sal quit smoking; Anne,
through sheer willpower; Sal, through
drugs and therapy.
NOTE: The comma has replaced "prefer" in the first example and "quit
smoking" in the second.
Comma - Position or Location:
Use commas to enclose or separate a phrase denoting residence, position, or location:
Paul Thorn, 418 Front Street, was the
best man.
John Alton, first place last year, is the
favorite again.
Seat fourteen, in the front row, is mine
for the season.
Comma - Questions:
Use a comma after a question that is not emphatic within a sentence if the sentence is not a direct quotation:
What's the use, we've lost.
But if the question is emphatic, insert a question mark in place of the comma:
Who cares? is the question.
Comma - Quotations:
Use a comma to set off direct quotations in dialogue form:
"A lot of good that does me," she said.
He told the press, "First things first."
Do not use a comma to set off an indirect (paraphrased) quotation:
He told me that it couldn't be done.
Comma - Series:
Use commas to separate words or phrases in a series:
We dined upon roots, berries, tree bark,
wild grains and seeds, and the
occasional slug or grub.
NOTE: The comma preceding the conjunction and before the final
item in the series is optional.
Do not use commas when conjunctions connect all the items in a series:
We drank and frolicked and sang and
howled till dawn.
Use commas before and after "etc." when it ends a series:
Baseball is an equipment–intensive
sport, one that requires bats, balls,
bases, gloves, etc., to be played.
NOTE: Since "etc." actually means "and so on," it always supplies its
own conjunction.
Transitional Words & Phrases:
Use commas to enclose or separate a transitional word or phrase when a pause is needed to emphasize or clarify the meaning of the sentence:
Indeed, he had taken them all.
His was a rough life, it is true, one that was
filled with many disappointments.
If the sentence is short and the meaning is clear, the transitional word or phrase need not be enclosed in or separated by commas:
The shortstop therefore made the play.
The conductor nonetheless released the brake.
When the transitional word or phrase joins two independent clauses, it should be preceded by a semicolon and followed by a comma:
He could not afford to buy such an expensive
car; moreover, it will have depreciated
significantly before he makes the final
payment.
Use a comma when a sentence begins with "yes," " no," "why," or "well":
