1. A workshop brought to you by the Purdue University Writing Lab
Conquering the Comma
Rationale: Welcome to “Conquering the Comma.” This presentation is designed to acquaint your students with the rules of comma usage, including placement in compound sentences, after introductory elements, with dependent phrases and clauses, around nonessential elements, in a series, and with adjectives. This presentation will also cover methods for avoiding a common comma error—the comma splice. The twenty-seven slides presented here are designed to aid the facilitator in an interactive presentation of the elements of comma usage. This presentation is ideal for the beginning of a composition course, the assignment of a writing project, or as a refresher presentation for grammar usage.
This presentation may be supplemented with OWL handouts, including “Using Commas” ( “Commas after Introductions” ( and “Commas with Non-essential Elements” (
Directions: Each slide is activated by a single mouse click, unless otherwise noted in bold at the bottom of each notes page.
Writer and Designer: Jennifer Liethen Kunka
Contributors: Muriel Harris, Karen Bishop, Bryan Kopp, Matthew Mooney, David Neyhart, and Andrew Kunka
Developed with resources courtesy of the Purdue University Writing Lab
Grant funding courtesy of the Multimedia Instructional Development Center at Purdue University
© Copyright Purdue University, 2000.
A workshop brought to you by
the Purdue University
Writing Lab
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2. What Is a Comma?
A comma is a punctuation mark that indicates a pause is needed in a sentence.
Commas help to clarify meaning for the reader. ,
Key Concepts: The facilitator may choose to invite the audience to respond to the title question and allow participants to discuss the function of the comma. Many writers become frustrated with comma usage because they are unsure of where to place them in their sentences. This presentation is designed to demystify the placement and usage of commas.
The facilitator may stress to participants that commas should not be ignored in writing; they are often needed to clarify meaning within a sentence and can help to avoid confusion.
Click mouse after title question to reveal each response.
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3. Clauses and Phrases
A clause is a group of words that contains both a subject and a verb that complement each other.
A phrase is a group of words that does not contain a subject or a verb that complement each other.
Key Concepts: This slide articulates the basic differences between a clause and a phrase. The facilitator may stress the importance of understanding these definitions for understanding comma placement.
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4. Sentence Structure: Independent Clause
A complete sentence has two components, a subject and a verb.
The subject and verb must form a complete thought to be considered an independent clause.
Key Concepts: This slide explains the structure of an independent clause, the primary building block for the development of any sentence. An independent clause requires a subject and a verb that can stand as a complete thought. Sentences can be very short, as the one detailed in the slide. The facilitator may ask the audience to identify the subject and verb in the example.
Click mouse after text appears to reveal picture and sample sentence.
Click mouse after sample sentence to reveal the labels “subject” and “verb.”
The couple dances.
The couple dances.
subject (S) verb (V)
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5. Sentence Structure: Compound Sentence
A sentence that contains two independent clauses joined by a coordinating conjunction is called a compound sentence.
A conjunction joins words, phrases, and clauses together in a sentence.
Conjunctions
for
and
nor
but or
yet so
Sentence Structure: Compound Sentence
Key Concepts: This slide explains the structure of a compound sentence and the role of a conjunction. An easy method for remembering the seven coordinating conjunctions is the acronym “fan boys.”
Click mouse at the end of the first column.
Click mouse at the end of the conjunction list to reveal the acronym.
FAN BOYS
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6. Sentence Structure: Compound Sentence
The comma in a compound sentence is placed before the coordinating conjunction.
Andy built a snowman, and Jeff played with his dog.
S V conj.
Andy built a snowman, and
Jeff played with his dog.
S V
Example: This slide exemplifies the location of a comma in a compound sentence, before the coordinating conjunction. The facilitator may ask participants to identify the subjects, verbs, and conjunction in the example.
Click after example sentence appears to reveal parts of speech.
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7. Sentence Structure: Compound Sentence
Where would you place the comma in the following sentence?
Example: This slide provides participants with an opportunity to locate the correct position for the comma within the sample sentence. The facilitator may also invite students to identify the subjects, verbs, and conjunction in the sentence.
Click mouse after sample sentence to reveal the comma.
Click mouse after the comma to reveal parts of speech.
Dan struggled with his homework so his father helped him.
Dan struggled with his homework, so his father helped him.
S V conj. S V
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8. Sentence Structure: Dependent Clause
A dependent clause contains a subject and verb, but the clause cannot stand independently.
Dependent clauses can often be identified by the use of dependent clause markers.
Some dependent clause markers:
though
although
unless
after
before
once
whether
because
since
when
while
until if as
Sentence Structure: Dependent Clause
Key Concepts: This slide explains the definition of a dependent clause. The dependent clause markers can help writers identify clauses that cannot stand alone within a sentence.
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9. Sentence Structure: Dependent Phrases and Clauses
Dependent phrases and clauses help to clarify and add detail to an independent clause.
Dependent clauses may appear at the beginning, middle, or end of a sentence.
Key Concepts: This slide further clarifies the role of dependent phrases and clauses within a sentence.
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10. Introductory clause= dependent clause located at the beginning of a sentence
When a dependent clause is placed at the beginning of a sentence, place a comma between the independent clause and the dependent clause.
Key Concepts: An introductory clause is a dependent clause located at the beginning of a sentence. After an introductory clause, a comma is needed to distinguish it from the independent clause.
Activity: The facilitator may choose to ask students to identify the independent and dependent clauses, the subjects, the verbs, and the dependent clause marker in the sample sentence.
Click mouse to reveal the parts of speech.
When Elizabeth called 911, the firemen rushed to her rescue.
When Elizabeth called 911, the firemen rushed to her rescue. DCM S V S V
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11. Where would you place the comma in the following examples?
Introductory Clause
Where would you place the comma in the following examples?
Since it was raining, we decided to go to the movies. DCM S V S V
Since it was raining we decided to go to the movies.
Once the movie began, I fell asleep.
DCM S V S V
Once the movie began I fell asleep.
Activity: This interactive slide invites participants to place commas after the introductory clauses in each sentence. Again, the facilitator may ask students to identify the parts of speech in each example.
Click mouse to reveal parts of speech, and then click again to reveal each example.
After the movie ended, we went out for coffee.
DCM S V S V
After the movie ended we went out for coffee.
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12. Dependent Clauses
When a dependent clause is located after an independent clause, DO NOT place a comma between the two.
I went on the roller coaster because my brother dared me.
S V DCM S V
Activity: When a dependent clause follows an independent clause, commas are not used. Facilitators may choose to ask students to identify the parts of speech in each example.
I became very sick when the
S V DCM
roller coaster zoomed upside down.
S V
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13. A Common Comma Error: The Comma Splice
A comma splice is an error in which two independent clauses are joined by a comma.
The Internet has revolutionized the business world,
S V
online sales have increased dramatically this year.
S V
We had a nice time, I hope we can meet again soon.
S V S V
A Common Comma Error: The Comma Splice
Key Concepts: One of the most prevalent comma errors is the comma splice—the placement of a comma between two independent clauses.
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14. To Correct a Comma Splice
Insert a conjunction between the two independent clauses.
Start a new sentence.
Insert a semi-colon between the two independent clauses (only in cases where the independent clauses are closely related in topic).
To Correct a Comma Splice
We had a nice time, and I hope we can meet again soon.
We had a nice time. I hope we can meet again soon.
The Internet has revolutionized the business world; online sales have increased dramatically this year.
Key Concepts: This slide enumerates several methods for correcting comma splices. The examples listed here are corrections of the comma splices in the previous slide.
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