Comma Rules
Provided by Academic Center for Excellence 1 Reviewed February 2012
Comma Rules
Rule One
Put a comma before coordinating conjunctions (for, and, nor, but, or, yet, so--remember
the acronym FANBOYS) only if they connect two independent clauses (a clause that
is capable of standing alone as a sentence).
independent clause + conjunction + independent clause = comma before conjunction
• Jerry picked vegetables, and Bob mowed the lawn.
• I did not bring an umbrella in the rain, nor did I wear a raincoat.
Rule Two
Do not put a comma before coordinating conjunctions (FANBOYS) if they connect
an independent clause with a dependent clause (a group of words that cannot stand
alone as a sentence).
independent clause + conjunction + dependent clause =
no
comma before conjunction
• The teacher scolded the boy for being late and sent him to the office.
• We watched the sky and hoped to see a shooting star.
Rule Three
Put a comma after words, phrases, and clauses in a series.
• Dogs, cats, and birds are common household pets. (words)
• The hound ran down the hill, through the meadow, and into the forest in
pursuit of the rabbit. (prepositional phrases)
• When the weather warms up, when the snow is melted, and when the
roads are clear, school will be back in session. (three dependent clauses
followed by an independent clause)
Provided by Academic Center for Excellence 2 Comma Rules
Reviewed February 2012
Rule Four
Put a comma between coordinate adjectives. (They are coordinate if they sound
natural when they are either reversed or joined by and.)
• The road dwindled into a rough, narrow path.
or
• The road dwindled into a narrow and rough path.
The comma does not separate adjectives when they sound unnatural when switched
or separated by and.
• Correct: She gave the teacher a large red apple.
• Incorrect: She gave the teacher a red and large apple.
Rule Five
Set off long introductory dependent clauses and phrases (four or more words) with a
comma. These clauses and phrases do not include the subject and verb of the sentence, and
they cannot stand alone as complete sentences.
• At the beginning of spring, flowers began to bloom.
• Although the prices were reduced, they were still absurdly high.
• Having finished his homework, the boy was permitted to go outside and
play.
• Forgetting to set her alarm clock, Ann woke up to find she was three
hours late for work.
• A studious and hard-working student, Thomas turned in every
assignment on time.
Commas are optional after introductory word groups that are not four words or
more.
• During summer we go on vacation.
• On Fridays we order pizza.
Provided by Academic Center for Excellence 3 Comma Rules
Reviewed February 2012
Rule Six
If the dependent clause comes after the independent clause, no comma is needed.
• We went to the store to buy school supplies since the new school year was
about to begin.
• English is my favorite subject because I love to read and write.
• The boy felt nervous even though he had been to the dentist before.
Rule Seven
Use commas around nonessential words, phrases, and clauses that interrupt the flow
of the sentence. If these words are dropped, the sentence will still make sense and retain its
basic meaning.
• John, the boy who drives the ice cream truck, is my brother.
• John is my brother. (the sentence retains the basic meaning without “the boy
who drives the ice cream truck”)
• The pillow, soft and fluffy, cushioned my head as I napped on the
hammock.
• The pillow cushioned my head as I napped on the hammock. (sentence still
makes sense, retains basic meaning)
Do not use the commas if the clause is essential to the meaning of the sentence and
cannot be taken out.
• Everyone who does their homework and studies will make an “A.”
• Everyone will make an “A.” (meaning is not the same, it is not guaranteed
that everyone will make an “A”)
• All the apples which were brown and rotted were thrown away.
• All the apples were thrown away. (meaning is not the same, not all of the
apples will be thrown away)
Provided by Academic Center for Excellence 4 Comma Rules
Reviewed February 2012
Rule Eight
Use commas to separate a direct quotation from the rest of the sentence.
• The instructor warned, “Students who do not study hard will fail the test.”
• Mother asked, “Who wants to go get ice cream?”
• “Yes,” the store clerk replied, “we do have this shirt in your size.”
Rule Nine
Use a comma to separate sentence elements to create the intended meaning.
• Still water is very refreshing.
• Still, water is very refreshing. (the comma changes the meaning)
• When we visited John, Robert came along.
• When we visited, John Robert came along.
Rule Ten
Use a comma to set off most conjunctive adverbs (however, otherwise, therefore, similarly,
hence, on the other hand, and consequently). But do not use a comma after the conjunctive
adverbs then, thus, soon, now, and also. In the following examples, a semicolon is used to
separate two independent clauses.
• The sick woman needs to be given treatment; otherwise, her illness will
become fatal.
• Mark’s goals were materialistic; therefore, he discarded any career choices
that offered only minimal salaries.
• The maid washed the dishes and mopped the floor; however, she forgot to
make the beds.
• We need to evacuate the beach quickly; soon there will be a severe
thunderstorm.
