First-Year English FAQs
Use these five rules for placing commas:
1. Use a comma between two complete
sentence linked together with a coordinating conjunction.
2. Use a comma to link items in
series and coordinate adjectives.
3. Use a comma to separate introductory
sentence elements longer than five words from the main part of the sentence.
4. Use a pair of commas to set off
extra information in sentences.
5. Use the comma for miscellaneous
items like clarity and to separate dates, addresses, and so on.
1. Use a comma between two complete sentences linked
together with a coordinating conjunction.
(This rule was previously explained in the section "Sentence
Punctuation Errors.")
There are only seven coordinating conjunctions--for, and, nor, but, or, yet, and so. You should memorize these seven coordinating conjunctions so that when you are trying to punctuate complete sentences you know when to use a comma and when to use an end mark of punctuation--period, semi-colon, colon, question mark, or exclamation point.
| complete sentence 1 | comma + for | complete sentence two |
| complete sentence 1 | comma + and | complete sentence two |
| complete sentence 1 | comma + nor | complete sentence two |
| complete sentence 1 | comma + but | complete sentence two |
| complete sentence 1 | comma + or | complete sentence two |
| complete sentence 1 | comma + yet | complete sentence two |
| complete sentence 1 | comma + so | complete sentence two |
Example:
The boy went to the store, but he never returned.
sentence 1 comma + but sentence 2
Errors with two complete sentences linked together with a coordinating conjunction occur frequently in student papers.
2. Use a comma to link items in series and
coordinate adjectives.
Items in a Series
In a complete sentence, coordinating conjunctions normally
link two words or two phrases without a comma.
Examples:
red and black
(coordinating conjunction links two words)running around the gate and sliding down the sidewalk
(coordinating conjunction links two phrases)
In these two examples there is no need for a comma between the word "red" and "and" nor between "running around the gate" and "and." If you put a comma between either the set of words or the set of phrases, you would be using the comma unnecessarily. This error would likely be noted as part of your paper's grade because your use of the comma in these situations would signal to the instructor that you do not know when to use a comma with a coordinating conjunction.
Unnecessary commas are a common misuse of the comma in student writing.
When there are more than three words or more than three phrases in series, you must use a comma to replace the "and" that has been removed from the series. The comma between the last two items in the series is optional. As a writer you can choose when to include it. However, this comma must be included if the last item in the series and the second to the last item in the series could be confused.
Examples:
red and black and blue
running to the gate and sliding down the sidewalk and walking to the door
When the "and" is removed between "red" and "black" and between "running to the gate" and "sliding down the sidewalk," this "and" must be replaced with a comma:
red, black and blue
(essential comma)running to the gate, sliding down the sidewalk and walking to the door
(essential comma)
The comma between the last two items in a series "black" and "blue" and "sliding down the sidewalk" and "walking to the door" is optional and may be included at the writer's discretion unless the last two items in the series could be misread as a single idea.
red, black, and blue
(writer's choice comma)running to the gate, sliding down the sidewalk, and walking to the door
(writer's choice comma)
Errors with items in a series comma occur infrequently in student papers.
Coordinate Adjectives
When there are at least two adjectives (thin, attractive)
before a noun (woman) and grammatically the word "and" can be inserted between
the two adjectives, you must use a comma. However, if the coordinating
conjunction "and" cannot be inserted logically between these two adjectives,
no comma is needed.
Example:
the thin and attractive model
When the "and" is removed for quicker reading, a comma must be inserted
the thin, attractive model
Errors with coordinate adjectives occur infrequently in student papers.
3. Use a comma to separate introductory sentence
elements longer than five words from the main part of the sentence.
When the main part of any sentence is prefaced by an introductory phrase or clause that is longer than five words, insert a comma between the introductory element and the main part of the sentence. Do not confuse introductory elements with extra information that begins a sentence. Extra information like the phrase "in fact" is always followed by a comma regardless of its length. To use the comma correctly, it is important to distinguish which words that come before the main sentence are introductory elements and which are extra information words or phrases.
Example of introductory phrase five words or longer:
After bathing and resting a while, the prime minister returned to drafting his speech.
The underlined words cannot stand alone as a sentence when the word "after" is removed, so the introductory element is a phrase, not a clause.
Example of introductory clause longer than five words:
After we finished our homework, we decided to watch television.
The underlined words can stand alone as a sentence when the word "after" is removed, so the introductory element is a clause not a phrase.
Example of a beginning parenthetical element:
In fact, after bathing and resting awhile, the prime minister returned to drafting his speech.
In this case even though the first few words of the sentence
do introduce, these words are extra information and regardless of their
length are set off with a comma.
4. Use a pair of commas to set off extra information
in sentences.
When you put extra information in a sentence, set off this extra information within the sentence with a pair of commas. When the extra information introduces the sentence, use a comma between the extra information and the main part of the sentence. When the extra information or after thought concludes the sentence, set the extra information off from the main part of the sentence with one comma and conclude the extra information with the period.
Example of extra information introducing a sentence:
Therefore, John gave up his legal right to an attorney.
The underlined word does not change the basic meaning of the sentence and is therefore parenthetical.
Example of extra information within a sentence:
John, the death row inmate, gave up his legal right to an attorney.
The underlined words do not change the basic meaning of the sentence and are therefore parenthetical.
Example of extra information at the end of a sentence:
John gave up his legal right to an attorney, feeling like he had no hope of a fair trial.
The underlined words do not change the basic meaning of the sentence and are therefore parenthetical.
In addition to commas, dashes--typed as two hyphens unless you have a dash on your computer keyboard--and parentheses can also be used to set off extra information in your text.
Like the period, the semi-colon, and the colon, all three marks--the comma, the dash, and the parenthesis--have the same punctuation use, but these marks say something slightly different to the reader. Parentheses tell the reader that what is inside these marks is extra information, but he may not want to read it. Dashes tend to emphasis the extra information contained within, and commas tend to give the extra information neutrality, suggesting to the reader that he or she can decide to read the extra information or not read it.
Mistakes with parenthetical items occur occasionally in student writing.
5. Use a comma for miscellaneous items like clarity
and to separate dates, addresses, and so on.
Mistakes with miscellaneous commas occur occasionally in student writing.