Quick Guide to
Commas
Wayne State University School of Social Work
What is a Comma?
 Merriam-Webster (2012) defines a comma as:
 “A punctuation mark, used especially as a mark of separation
within the sentence” (para. 1).
 Commas tell a reader to pause in a sentence much like a
driver yields to a blinking yellow before proceeding
(“Punctuation Made Simple”, n.d.).
http://lilt.ilstu.edu/golson/punctuation/comma.html
Clauses
 Independent Clause:
 A group of words that contain a subject and verb and
completes a thought.
 Example: Jess shopped for new running shoes.
Clauses
 Dependent Clause:
 A group of words that contain a subject and a verb but does not
express a complete thought.
 Example: When Jess shopped for new running shoes...(What
happened when Jess shopped for new running shoes?)
 Often, dependent clauses contain marker words.
 Marker words: after, as, as if, because, before, if, since, though,
unless, until, whatever, when, whenever, whether, and while (to
name a few).
Commas
 We use commas to separate independent clauses when joined
by a coordinating conjunction.
 Coordinating conjunctions: but, and, or, so, nor, yet, and for.
 Example: Jess shopped for running shoes, but the store was closed
 “Jess shopped for shoes.” and “The store was closed.” are
independent clauses joined by a comma and a coordinating
conjunction.
Commas
 We use commas following an introductory clause:
 Starter words for introductory clauses: although, if,
since, when, while.
 Example: While Jess was shopping for running shoes,
she misplaced her keys.
Commas
 We use commas in the middle of sentences “to set off clauses,
phrases, and words that are not essential to the meaning of
the sentence.” These are often called “parenthetical
elements” or “added information”
 Example: Last Wednesday, which was my birthday, was the pep
rally.
 Clues: Does the sentence still make sense if we take the clause
away?
 These can be very subjective.
http://owl.english.purdue.edu/owl/resource/607/02/
Commas
 We use commas to separate three or more words,
phrases, or clauses written in a series
 Jess’ new car was red, sporty, and fast.
 All of the above adjectives carry the same weight in
describing the noun.
Commas
 We use commas to set off phrases that express contrast.
 Example: Jess’ new running shoes were on sale, not regular price.
 We use commas to set off phrases at the end of the sentence
that refer to the beginning or middle of the sentence.
 Example: Jess ran the marathon enthusiastically, waving at the
crowds.
Commas
 We use commas to set off quoted elements.
 Example: As Jess stated, “I love my new running shoes.”
 We use commas to set off all geographical names, items in
dates (except the month and day), addresses (except the
street number and name), and titles in names.
 Examples:
 Detroit, Michigan
 June 27, 1976, is my birthday
 No comma needed to separate month/year (June 2012).
Comma Abuse
 There are many reasons for using commas, and only the most
common uses are listed.
 Yet the biggest problem that most students have with commas
is their overuse.
 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 to do so.
Comma Abuse
 We do not use commas to separate a subject and verb.
 Example: The most important quality in a person, is their sense of
humor.
 We do not use commas between the two verbs in a
compound predicate.
 Compound predicate: Usually tells us what the subject is doing,
or what is happening to the subject.
 Example: Jess put on her new running shoes, and began to run.
Semicolons
 As previously stated, we use commas after the first
independent clause when you link two independent clauses
with a coordinating conjunction.
 We use semicolons when two independent clauses are linked
with no connecting words (coordinating conjunctions).
 Example: It rained during Jess’ marathon; she managed to finish it
anyway.
Semicolons
 We also use a semicolon when two independent clauses are
joined together with a conjunctive adverb.
 Conjunctive adverb: however, moreover, therefore, otherwise,
thus, etc.
 Example: It rained during Jess’ marathon; however, she managed
to finish it.
Semicolons
 Do not use a semicolon with a coordinating conjunction.
 Conjunctions: and, but, or, nor, for, so, and yet.
 Example: Jess’ shoe became loose during the marathon; but she
managed to finish it. Not Correct.
 There is one instance in which it is appropriate to use a
semicolon with a coordinating conjunction.
 Within a list of items where commas are used to separate items.
A semicolon may be used to separate a grouping.
 Example: The winners are: John H. of Detroit, MI; Joan P. of
Dallas, TX; and Sam C. of Orlando, FL.
Further Reading
 New York Times
 http://opinionator.blogs.nytimes.com/2012/05/21/the-mostcomma-mistakes/
 APA Styl Manual
 p. 88, section 4.03
Thank you!
For further assistance with commas and semicolons, please
schedule an appointment with your Writing Tutor!