I don’t want to spend an awful lot of time on these “rules,” but I think it would help to refresh ourselves on some common grammar practices in Standard Edited American English. Please refer back to this page as you need to throughout the rest of the semester.

Coordinating Conjunctions

BOYSFAN–but, or, yet, so, for, and, & nor

Use commas to separate two independent clauses joined by a coordinating conjunction. Independent clauses are simply clauses that can stand alone as sentences–they contain a subject and a verb and a complete thought. Consider the following examples below:

• I wish you wouldn’t sleep in class. Your grade depends on your being awake and attentive during discussions.
• You can do well in class if you show up regularly. Not showing up to class regularly will affect your grade.
• I want to become a circus clown. I will go to the School of Clownology in Charlottesville, VA this fall to pursue my degree.

Let’s join those sentences with coordinating conjunctions:

• I wish you wouldn’t sleep in class, for your grade depends on you(r) being awake and attentive during discussions.
  • I realize “for” is a bit of a stilted way of writing. More likely you’d use the subordinating conjunction because without a comma:
    I wish you wouldn’t sleep in class because your grade depends on you(r) being awake and attentive during discussions.
  • More on that in the next section.
• You can do well in class if you show up regularly, but not showing up to class regularly will affect your grade.
  • “not showing up to class regularly” is a subject of the sentence and is doing something…well, it’s actually NOT doing something, but you understand what I mean.
• I want to become a circus clown, so I will go to the School of Clownology in Charlottesville, VA this fall to pursue my degree.

Subordinating Conjunctions

WWAABSET-O–when, while, after, although, because, since, even though, and others (too many to list)

Use commas with most subordinating conjunctions that introduce or open a sentence:

• When Mopsy was born, my parents got her from a neighbor. {You could even say, “After Mopsy was born, my parents got her from a neighbor.”}
• While you were away, I watched TV and read. {Notice that “While you were away” cannot stand alone as a sentence. Also, some readers scoff at using “while” for situations other than time; instead, they prefer “although.”}
• Because I want a life free of difficulty, I do not plan to have children.
• Although I prefer Star Wars to Star Trek, I usually prefer science fiction narratives to fantasy works (books, movies, etc).
• Even though the Patriots are a great team, they couldn’t cheat their way to a Super Bowl win.

Conjunctive Adverbs (aka. Transitional Words and Hedging Words)

• The adverbs: however, furthermore, also, instead, nevertheless, first, second, third, finally, next, and many others
• The introductory phrases: for example, in fact, for instance, in conclusion, therefore, of course, in other words, and many others

Use a comma to set off introductory words and phrases. Since these words allow writers to transition smoothly from sentence to sentence, they often follow a semicolon (;) before beginning a new independent clause. For example,

I would really love to come to your wedding; however, I can’t keep my mouth shut when asked, “Does anyone know why these two should not be joined in matrimony? Speak now or start placing bets on when they’ll divorce.” Therefore, please don’t expect a gift from me, and please don’t have any children–no need to continue your horrific lineage!

Of course, too many of these phrases affects you concision, so use sparingly and only for strategic emphasis–not all the time.

Notable Exceptions

As with most rules and laws, there are some exceptions to comma placement. Below is a statistically inaccurate list about which comma rules are adhered to more than others. Remember, your audience will have a lot to do with the style you choose. I’m more familiar with MLA style, but I’ve become increasingly aware of AP and APA style through the years.

• 100% (or close enough): Comma splices are nearly universally unacceptable; a comma splice is when a comma is used to join two or more independent clauses without a coordinating conjunction.
  Example: People with loud children shouldn’t be allowed in restaurants, they should just stay home and entertain themselves.
• 90% (or thereabouts): Commas normally appear with all coordinating conjunctions except when a sentence is very short; I have noticed that implied subjects often omit commas with coordinating conjunctions.
  Example: Go outside and cut me off a switch. {‘You’ is the implied subject. Both “Go outside” and “Cut me off a switch” are independent clauses. The speaker just isn’t saying “You go outside, and you cut me off a switch.”}
• 80% (or nowhere near): In some cases, introductory prepositional phrases do not need commas; however, no authority has definitively told me which phrases to put a comma after and which to not. Long ago, I taught a developmental grammar class, and the book we used claimed to use commas after introductory prepositional phrases of more than five words. Kolln & Gray recommend using a comma “for the opening prepositional phrase if it exceeds five to six words” (p. 228). I never knew that “rule” and later learned that some readers expected commas after all introductory prepositional phrases and some didn’t want them even after the five- to six-word introductory prepositional phrases.
  • Example: Over the past year, I have been preparing for the LSAT.
  • Example: On Tuesday, we ought to go out to lunch.{I believe the “On Tuesday” deal about not using commas is that it’s common to start out with that type of phrase, so most people drop the comma. In fact, journalists, who must conserve space in those tiny columns of print, seem to limit as many commas as possible. AP style (Associated Press) is a style used by many newspapers.}
• A No-No: Don’t use a comma to separate a sentence subject that begins with a preposition. For instance, you wouldn’t write the following:
  “Under the bridge, is where I drew some blood” because Under the bridge is the noun phrase containing the subject of that sentence, bridge. However, the following uses a comma appropriately: “Under the bridge downtown, I gave my life away.” In that sentence, I is the subject, and Under the bridge is the introductory prepositional phrase.
• 50% (and probably accurate): Use commas to set off items in a series…but which items? Yes, the plot thickens!
  Example: You need to study hard, rest, and stay focused to do well on the exam.
  Example: Go to the store and buy beer, chips, and beef jerky.
  {Depending on your style guideline, you may or may not omit the comma before the “and” in the above examples.}
• But there’s an issue with not using the “extra” comma: Consider the statement, “My uncle left me his property, houses, and cars.” With that “extra” comma, there’s no way to mistake that your uncle left you three distinct items–property (e.g., land), houses, and cars. However, if you said, “My uncle left me his property, houses and cars,” houses and cars comprise his property. When you use a comma to separate a noun from a following description, that description is an appositive. For instance, the sentence, “I wonder if it’s snowing in Chicago, a place north of here,” uses a place north of here to further describe Chicago.

That’s enough comma stuff for a lifetime. Pick up a grammar/style handbook to help you with these issues. Although I am more concerned with your content, proper mechanics is still important.