1. The Brenham Writing Room Created by D. Herring
Commas
The Brenham Writing Room
Created by D. Herring

2. Why use a Comma?
A comma is a punctuation mark that helps keep distinct ideas separate.
Commas signal meaning, so it is critical to use them correctly!

3. How do I use Commas correctly?
There are set guidelines for using commas. You must know and understand the rules of comma usage.
In particular, you must know and understand how to use
Commas between items in a series
Commas after introductory word groups
Commas around appositives and interrupters
Commas in compound sentences
Commas in complex sentences

4. Using Commas between Items in a Series
When you have a list of three or more items in a series, you must include a comma between each item. With the last item, the comma will come before the “and/or.”
We ate fish, shrimp, and oysters.
She wants to be a teacher, librarian, or counselor.
Do not include a comma when you have only two items in the series.
We ate fish and shrimp.
She wants to be a teacher or librarian.

5. 2. Using Commas after Introductory Word Groups
Use a comma after an introductory word, phrase, or clause to let your reader know when the main part of the sentence is starting.
However, it’s only the fifth week of the semester. (introductory word)
According to my teacher, I am doing well in my math course. (introductory phrase)
Because I didn’t study for the exam, I didn’t pass. (introductory clause)

6. 3. Using Commas with Appositives & Interrupters
What is an appositive?
An appositive comes directly after a noun and renames it.
Ms. Bonnie, our class tutor, really helped me improve my writing.
My favorite restaurant, TGI Fridays, just opened in College Station.
Ana, one of my 0321 students, won a scholarship to SHSU.
My English teacher, Mr. Herring, assigns a lot of homework.

7. Appositives & Interrupters cont.
What is an Interrupter?
An interrupter is an aside or transition that interrupts the flow of a sentence but doesn’t affect its meaning.
By the way, most of the students did well on the first writing assignment.
Some of the students, however, did not do well.
Many students, incidentally, received a better grade because they got help from the tutor.
Others, on the other hand, received lower grades because they didn’t take time for tutoring.

8. Appositives & Interrupters cont.
We use commas around appositives and interrupters to tell our readers that these elements provide extra information but are not essential to the meaning of a sentence. Wherever these elements fall in the sentence, they should be offset with commas.
By the way, most students passed 0320.
Most students, by the way, passed 0320.
Most students passed 0320, by the way.

9. Appositives & Interrupters cont.
It is important to understand how a transitional word is being used so that you can properly punctuate.
I did well on my math test; however, I did not do well on my English test. (transitional word as introductory element)
I did well on my math test; I did not, however, do well on my English test. (transitional word as interrupter)
I did well on my math test, however, I did not do well on my English test. (incorrect use—creates a comma splice!)

10. Appositives & Interrupters cont.
Sometimes an appositive is essential to the meaning of the sentence. When the meaning of the sentence would not be the same without the appositive, it should not be offset with commas.
The actor John Travolta has never won an Academy Award.
The actor has never won an Academy Award.
The clothing store Foleys has been bought out by another company.
The clothing store has been bought out by another company.

11. 4. Using Commas in Compound Sentences
When you have a compound sentence—two independent clauses joined together with a coordinating conjunction—you must use a comma before the coordinating conjunction.
We went out to dinner, and then we went to see a movie.
We wanted to go out to dinner, but we didn’t feel like going to the movies afterwards.

12. Compound Sentence continued
If you have a coordinating conjunction joining two clauses, but one is independent and the other is not, no comma is needed!
We went out to dinner and then to see a movie.
We wanted to go out to dinner but not to the movies.

13. 5. Using Commas in Complex Sentences
Complex sentences join an independent clause with a dependent clause or relative clause.
A dependent clause begins with a subordinating conjunction (dependent word) and cannot stand alone.
A relative clause begins with a relative pronoun (who, which, that) and cannot stand alone.

14. Commas with Dependent Clauses
When a dependent clause is used as an introductory clause, it is followed by a comma.
Because I didn’t study for the exam, I didn’t pass.
When you get to work, give me a call.
However, when a dependent clause comes at the end of the sentence, it is generally not preceded by a comma.
I didn’t pass because I didn’t study for the exam.
Give me a call when you get to work.

15. Commas with Relative Clauses
If a relative clause can be taken out of the sentence without changing the meaning, then it should be offset with commas.
My dog, who is a Beagle, barks too much.
My laptop, which weighs only five pounds, fits into my backpack.
My history teacher, who is about a hundred years old, just doesn’t understand me.

16. Relative Clauses continued
If a relative clause cannot be taken out of the sentence without changing the meaning, then it should not be offset with commas.
The man who stole my purse has been arrested.
The shirt that I bought yesterday already has a tear in it.
The English class that I’m taking in the fall meets on Tuesdays and Thursdays.

17. Relative Clauses continued
REVIEW:
When should I use that?
That is used to introduce a restrictive (essential) clause describing an animal or a thing.
When should I use which?
Which is used to introduce a nonrestrictive (non-essential) clause describing an animal or a thing.
When should I use who?
Who is used to introduce both a restrictive and nonrestrictive clause describing an animal or a person.

18. Relative Clauses continued
Incorrect: The man that stole my purse has been arrested.
Correct: The man who stole my purse has been arrested.
Incorrect: The English course which I’m taking this fall meets on TR.
Correct: The English course that I’m taking this fall meets on TR.
Incorrect: My laptop, that weighs five pounds, fits into my backpack.
Correct: My laptop, which weighs five pounds, fits into my backpack.