The correct use of commas can be confusing, but there are a few general rules that can clarify their use. First, some technical terms: A clause is a group of words that contains a subject and a predicate. The subject of a clause is who or what is being talked about. The predicate of a clause is what the subject is doing. An independent clause stands alone and expresses a complete thought. A dependent clause is does not stand alone and does not express a complete thought.

Compound Sentence Commas
A compound sentence contains two or more independent clauses connected either by a comma and a coordinating conjunction or by a semicolon.

1. Skim your paper, looking for the seven coordinating conjunctions: For, And, Nor, But, Or, Yet, So (Think FANBOYS.)
2. Stop at each of these words and see whether there is an independent clause on either side of it. If so, you have three options for correcting the sentence:
   1. Place a comma before the coordinating conjunction: The Aggie Senior Ring originated in 1889, and it serves as a link between seniors and former students.
   2. Connect these independent clauses using a semicolon: The Aggie Senior Ring originated in 1889; it serves as a link between seniors and former students.
   3. Write two separate sentences: The Aggie Senior Ring originated in 1889. It serves as a link between seniors and former students.

Introductory Commas
For introductory commas after dependent clauses, try this strategy:

1. Skim your paper, looking only at the first two or three words of each sentence.
2. Stop if one of these words is a dependent clause marker such as the following:
   after, although, as, as if, as long as, as soon as, because, before, if, in order that, since, so that, than, though, unless, until, when, whenever, wherever, while
3. If you see one of the words in the list above, you have found an introductory dependent clause. Place a comma between the last word of the dependent clause and the first word of the independent clause. Dependent clauses at the end of the sentence do not require commas.

Examples: When students at Texas A&M reach their senior year, they are called "zips." They are called "former students" after they graduate because there are no ex-Aggies.

For other introductory commas, use the following strategies:

1. Skim your paper, looking only at the first word of each sentence.
2. Stop if the word or phrase: 
   •  Ends in -ing
   • Begins with to
   • Begins with a preposition (about, above, across, against, among, around, at, after, before, behind, beside, between, beyond, by, down, during, into, for, from, in, except, near, of, off, to, over, past, throughout, through, toward, on, up, without, until, with, under are some common ones.)
   • Is an introductory word (well, yes, moreover, etc.)
3. Place a comma before the first word of the independent clause.

Examples: Attending an Aggie football game, one can see the bond among Aggies. To encourage their team, fans in the stands wave their 12th Man towels.

Disruptive Commas
For disruptive commas between compound verbs or objects:

1. Skim your paper, stopping only at the coordinating conjunctions:
   and, but, or, nor, for, yet, so (Think A. B. Fonsy.)
2. Check to see whether there is an independent clause on each side of the conjunction. If so, place a comma before the conjunction. If not, do not place a comma before the conjunction.

Disruptive comma: The football games are thrilling, but are not the only example of the Aggie Spirit.
Correct: The football games are thrilling but are not the only example of the Aggie Spirit.

For disruptive commas between subjects and verbs:

1. Find the subject and verb in each of your sentences.
2. Make sure that you have not separated the subject from its verb with one comma.

Disruptive comma between subject and verb: Yell Leaders elected by the student body, build motivation and spirit for many events in Aggieland.
Correct: Yell Leaders elected by the student body build motivation and spirit for many events in Aggieland.

Series Commas 

1. Skim your paper, stopping at the conjunctions and or or.
2. Check to see if these conjunctions link words, phrases, or clauses written in a series.
3. If so, place commas after all of the words, phrases, or clauses in the series except the last ones. Example: Reveille, the Quad, and Wildcatting are all traditions unique to TAMU.

Non-essential Commas

1. Skim your paper, looking for a phrase or clause in each sentence that explains or gives more information about a word or phrase that comes before it.
2. If you can delete the phrase or clause and still keep the meaning, the phrase or clause is usually non-essential and needs two commas, one before and one after unless the phrase or clause is at the end of the sentence. In that case, use one comma before it.
3. As an alternative test for a non-essential phrase or clause, try saying “by the way” before it. If that seems appropriate to the meaning, the phrase or clause is probably non-essential. Example: Non-regs, undergraduate students not in the Corps of Cadets, were allowed to attend Texas A&M for the first time during the 1960's.