Comma: Major Uses and Worst Abuses
1. Use a comma to separate the elements in a series (three or more things),
including the last two. "He hit the ball, dropped the bat, and
ran to first base." You may have learned that the comma before
the "and" is unnecessary, which is fine if you're in control
of things. However, there are situations in which, if you don't use
this comma (especially when the list is complex or lengthy), these last
two items in the list will try to glom together (like macaroni and cheese).
Using a comma between all the items in a series, including the last
two, avoids this problem. This last comma-the one between the word "and"
and the preceding word-is often called the serial comma or the
Oxford comma. In newspaper writing, incidentally, you will seldom
find a serial comma, but that is not necessarily a sign that it should
be omitted in academic prose.
2. Use a comma + a little conjunction (and, but, for, nor, yet,
or, so) to connect two independent clause, as in "He hit
the ball well, but he ran toward third base."
Contending that the coordinating conjunction is adequate separation,
some writers will leave out the comma in a sentence with short, balanced
independent clauses (such as we see in the example just given). If there
is ever any doubt, however, use the comma, as it is always correct in
One of the most frequent errors in comma usage is the placement of a
comma after a coordinating conjunction. We cannot say that the comma
will always come before the conjunction and never after, but it would
be a rare event, indeed, that we need to follow a coordinating conjunction
with a comma. When speaking, we do sometimes pause after the little
conjunction, but there is seldom a good reason to put a comma there.
3. Use a comma to set off introductory elements, as in "Running
toward third base, he suddenly realized how stupid he looked."
It is permissible to omit the comma after a brief introductory element
if the omission does not result in confusion or hesitancy in reading.
If there is ever any doubt, use the comma, as it is always correct.
4. Use a comma to
set off parenthetical elements, as in "The Founders Bridge, which
spans the Connecticut River, is falling down." By "parenthetical
element," we mean a part of a sentence which can be removed without
changing the essential meaning of that sentence. The parenthetical element
is sometimes called "added information." This is the most difficult
rule in punctuation because it is sometimes unclear what is "added"
or "parenthetical" and what is essential to the meaning of a
5. Use a comma to separate coordinate adjectives. You could think
of this as "That tall, distinguished, good looking fellow" rule
(as opposed to "the little old lady"). If you can put an and
or a but between the adjectives, a comma will probably belong there. For
instance, you could say, "He is a tall and distinguished fellow"
or "I live in a very old and run-down house." So you would write,
"He is a tall, distinguished man" and "I live in a very
old, run-down house." But you would probably not say, "She is
a little and old lady," or "I live in a little and purple house,"
so commas would not appear between little and old or between little and
6. Use a comma to set off quoted elements. Because we don't use
quoted material all the time, even when writing, this is probably the
most difficult rule to remember in comma usage. It is a good idea to find
a page from an article that uses several quotations, photocopy that page,
and keep it in front of you as a model when you're writing. Generally,
use a comma to separate quoted material from the rest of the sentence
that explains or introduces the quotation:
- Summing up this
argument, Peter Coveney writes, "The purpose and strength of the
romantic image of the child had been above all to establish a relation
between childhood and adult consciousness."
If an attribution
of a quoted element comes in the middle of the quotation, two commas will
be required. But be careful not to create a comma splice in so doing.
- "The question
is," said Alice, "whether you can make words mean so many
- "I should
like to buy an egg, please," she said timidly. "How do you
Be careful not to
use commas to set off quoted elements introduced by the word that or quoted
elements that are embedded in a larger structure:
- Peter Coveney writes
that "[t]he purpose and strength of . . ."
- We often say "Sorry"
when we don't really mean it.
And, instead of a
comma, use a colon to set off explanatory or introductory language from
a quoted element that is either very formal or long (especially if it's
longer than one sentence):
- Peter Coveney had
this to say about the nineteenth-century's use of children
in fiction: "The purpose
and strength of . . . . "
7. Use commas to set
off phrases that express contrast.
- Some say the world
will end in ice, not fire.
- It was her money,
not her charm or personality, that first attracted him.
- The puppies were
cute, but very messy.
(Some writers will leave out the comma that sets off a contrasting phrase
beginning with but.)
8. Use a comma to
avoid confusion. This is often a matter of consistently applying rule
- For most the year
is already finished.
- For most, the year
is already finished.
- Outside the lawn
was cluttered with hundreds of broken branches.
- Outside, the lawn
was cluttered with hundreds of broken branches.
9. Grammar English's
Famous Rule of Punctuation: Never use only one comma between a subject
and its verb. "Believing completely and positively in oneself
is essential for success." [Although readers might pause after the
word "oneself," there is no reason to put a comma there.]
Reasons: Between a city and a state [Hartford, Connecticut], a date
and the year [June 15, 1997], a name and a title when the title comes
after the name [Bob Downey, Professor of English], in long numbers [5,456,783
and $14,682], etc. Although you will often see a comma between a name
and suffix - Bob Downey, Jr., Richard Harrison, III - this comma is no
longer regarded as necessary by most copy editors, and some individuals
- such as Martin Luther King Jr. - never used a comma there at all.
Commas with Caution!
As you can see, there
are many reasons for using commas, and we haven't listed them all. Yet
the biggest problem that most students have with commas is their overuse.
Some essays look as though the student loaded a shotgun with commas and
blasted away. Remember, too, that a pause in reading is not always a reliable
reason to use a comma. Try not to use a comma unless you can apply a specific
rule from this page to do so.
Concentrating on the
proper use of commas is not mere form for form's sake. Indeed, it causes
writers to review their understanding of structure and to consider carefully
how their sentences are crafted.
Darling and Capital Community College, Copyright 2002; Hartford, Connecticut.