3. So, what is a comma, anyway?
• A comma is a punctuation mark that separates words or groups of
words (phrases) within sentences.
• They keep ideas distinct from one another.
4. When do we use commas?
• Between independent clauses.
• Between one dependent clause and one independent clause, respectively.
• In a series.
• After introductory phrases and transitional words and phrases.
• After and before a direct address.
• After and before appositive phrases.
• After and before nonrestrictive clauses.
• In dates and addresses.
5. Between Independent Clauses (Compound)
• Independent clauses are also known as complete sentences. They are
independent of any other sentence.
• They contain a complete thought:
• “I went home” is an independent clause.
• It has a subject, “I,” a verb, “went,” and an object, “home.”
• “I watched television” is also an independent clause.
• When you put two together, you must use a comma followed by a
• I went home, and I watched television.
• I went to work, but I forgot my phone.
• You can play in your room, or you can ride your bike.
6. Between a Dependent and an Independent Clause
• A Dependent Clause is an incomplete sentence. It is dependent on
whatever clause or clauses that are connected to it.
• If the dependent clause comes before an independent clause, you must
use a comma without a conjunction:
• If you want to graduate, you have to study.
• If the dependent clause comes after the independent clause, there is no
• You have to study if you want to graduate.
7. In a Series
• A series is three or more words, phrases, or clauses listed one after the other in a
• A comma must be placed between each separate item and a conjunction before the
• I went to the store and bought milk, eggs, cheese, and butter.
• Yesterday I went to the store, walked the dog, played videogames, and watched television.
• We can go to the movies, the park, or the museum.
• A subject does not need to be placed at the beginning of each item unless the item is
the object of a new one:
• I went to the store, Joe watched television, and the kids played in their rooms.
• If you have only two items, they are separated by a conjunction, but not a comma:
• We have eggs and milk.
• My life is exciting and full of surprises.
8. After Introductory Phrases and Transitional Words or
• An introductory phrase introduces a sentence.
• A comma must be placed after the phrase:
• To keep fit, I exercise three times a week.
• Crossing the street, Henry fell into a manhole.
• A transitional word or phrase transitions from one idea to another:
• In conclusion, I believe we should have soda machines in all classrooms.
• He was, of course, an adult when he started his first job.
9. After and Before a Direct Address
• A Direct Address is someone’s name or a pronoun that someone uses
• A comma must be placed before or after the direct address, or in both
places, depending on where the direct address is located:
• Molly, come here.
• Come here, Molly.
• Come here, Molly, and look at this.
10. After and Before Appositive Phrases
• An Appositive Phrase renames, identifies, or describes a noun or
• A comma must be placed before and after these phrases:
• My friend, Anna Villaplana, is visiting Spain this month.
• His boss, who always has something supportive to say, is out this week with a
• My friend’s name is George Lopez, a man with a sense of humor.
11. After and Before Nonrestrictive Clauses
• Nonrestrictive Clauses are clauses that add extra, non-essential
information to a sentence. They do not change the meaning of the
sentence if removed.
• A comma must be placed before and after a nonrestrictive clause to set
it off from the sentence:
• Heart attacks, the number one cause of death in the United States, have
increased since 2002.
• Restrictive Clauses contain information that is essential to the
meaning of the sentence and do not need commas:
• Many rock stars who recorded hits in the 1950’s made little money from their
12. In Dates and Addresses
• Use commas in dates to separate the day of the week from the month,
the day of the month from the year, and the year from the rest of the
• Tuesday, May 5, 1998, was the first Cinco de Mayo we celebrated in the US.
• Use commas in addresses to separate the street address from the city,
the city from the state or country, and the country from the rest of the
• The office at 221B Baker Street, London, England, belonged to the famous fictional
detective Sherlock Holmes.
13. At the Beginnings and Endings of Quotes
• When writing a quote, a comma must be placed before and after if it is
in the middle of a sentence:
• He said, “My life sucks,” and left the room.
• According to the New York Times, “many people cannot go an hour without
looking at their phones,” and some have even reported having chronic headaches
• David Eddings once said, “A day in which you learn something isn’t a complete
• The New York Times was “strong in its belief on this topic,” and refused to
15. What are semicolons, anyway?
• Semicolons are punctuation marks that separate two complete
thoughts (independent clauses).
• These are normally used to connect two ideas that are related to each
other without using a period or comma and conjunction.
• A semicolon has the same effect as a period. It denotes a full stop and
has no connecting word before or after.
• His grades were horrible; his teacher said he had trouble paying attention in class.
16. What are colons, anyway?
• A colon is a punctuation mark indicating.
• that a writer is introducing a quotation or a list of items.
• that a writer is separating two clauses of which the second expands or illustrates
• I bought three things: milk, eggs, and cheese.
• His grades were horrible: he had a D or an F in every class.
18. What are apostrophes, anyway?
• An apostrophe is a punctuation mark ( ’ ) used to indicate either
possession or the omission of letters or numbers.
• Harry’s coat is blue.
• Robert Jordan’s The Wheel of Time is an excellent series.
• Harriet Jones’ book is just as good.
• I can’t go to work today because I’m sick.
• We went to China during the summer of ‘99.
• Its and It’s
• The word “its” is possessive: The cat is a beautiful animal; its eyes are gorgeous.
• The word “it’s” is a contraction standing for “it is”: It’s almost time for bed.
19. What are Quotation Marks, anyway?
• Quotation marks are each of a set of punctuation marks, single or double, used either
to mark the beginning and end of a title or quoted passage or to indicate that a word
or phrase is regarded as slang or is being discussed rather than used within the
• We use quotation marks for quotes:
• I said, “Go clean your room.”
• We use them to denote slang words and well-known ideas:
• Everyone comes to the US to find their “American Dream.”
• We use them to denote a title of a poem, short story, or article:
• George McFarlan wrote an article called “The Dream of Life.”
• We use single quotes to denote quotes within a quote:
• According to the NY Times, “George Martin wrote three books in two years, saying, ‘I can’t believe
I did that!’ and plans to write more.”