Commas

an icon showing a commaCommas: these little horrors haunt the nightmares of many a professor after an evening of reading student papers. It seems nearly impossible to remember and apply the seventeen or so comma rules that seem to be given out as the standard, for example, “Use commas to set off independent clauses joined by the common coordinating conjunctions” or, “Put a comma before the coordinating conjunction in a series.”

You have probably also heard a lot of tips on using commas in addition to those rules: “Use one wherever you would naturally pause,” or “Read your work aloud, and whenever you feel yourself pausing, put in a comma.” These techniques help to a degree, but our ears tend to trick us, and we need other avenues of approach.

Quite honestly, instructors and students both make errors in comma usage, but, as Robert Browning says, “a man’s reach should exceed his grasp, / Or what’s a heaven for?” In other words, our almost inevitable failure at comma rules doesn’t mean we shouldn’t try. Perhaps the best and most instructive way for us to approach the comma is to remember its fundamental function: it is a separator. Once you know this, the next step is to determine what sorts of things generally require separation. This includes most transition words, descriptive words or phrases, adjacent items, and complete ideas (complete ideas contain both a subject and a verb).

Transition Words

Transition words add new viewpoints to your material; commas before and after transition words help to separate them from the sentence ideas they are describing. Transition words tend to appear at the beginning or in the middle of a sentence. By definition, a transition word creates context that links to the preceding sentence. Typical transition words that require commas before and after them include however, thus, therefore, also, and nevertheless.

  • Therefore, the natural gas industry can only be understood fully through an analysis of these recent political changes.
  • The lead prosecutor was prepared, however, for a situation like this.

Note: As was mentioned, these words require commas at the beginning or middle of a sentence. When they appear between two complete ideas, however, a period or semicolon is required beforehand:

  • Dr. Clint had been planning the Geology field trip with his research group for three months; however, when NASA called him onto a project, he couldn’t say no.
  • General Peters was retired. Nevertheless, he wanted to dictate policy in the new administration.

As you can see from these examples, a comma is always required after transition words.

Descriptive Phrases

Descriptive phrases often need to be separated from the things that they describe in order to clarify that the descriptive phrases are subordinate (i.e., they relate to the sentence context, but are less responsible for creating meaning than the sentence’s subject and verb). Descriptive phrases tend to come at the very beginning of a sentence, right after the subject of a sentence, or at the very end of a sentence.

  • Near the end of the eighteenth century, James Hutton introduced a point of view that radically changed scientists’ thinking about geologic processes.
  • James Lovelock, who first measured CFCs globally, said in 1973 that CFCs constituted no conceivable hazard.
  • All of the major industrialized nations approved, making the possibility a reality.

In each example, the phrase separated by the comma could be deleted from the sentence without destroying the sentence’s basic meaning. If the information is necessary to the primary sentence meaning, it should not be set off by commas. Let’s look at a quick example where comma usage conveys meaning:

  • Jefferson’s son, Miles, just started college.
  • Jefferson’s son Miles just started college

You would write the first sentence if Jefferson only has one son and his name is Miles. If Jefferson only has one son, then Miles is not needed information and should be set off with commas.

You would write the second sentence if Jefferson has multiple sons, and it is his son Miles who just got into college. In the second sentence, Miles is necessary information, because until his name is stated, you can’t be sure which of Jefferson’s sons the sentence is talking about.

This knowledge can be very helpful when you’re deciding whether or not to include commas in your writing, especially around the titles of books or articles you mention in your essay, where students tend to spray commas at the page. Often, the title is needed information.

 

Adjacent Items

Adjacent items are words or phrases that have some sort of parallel relationship, yet are different from each other in meaning. Adjacent items are separated so that the reader can consider each item individually.

The river caught fire on July 4, 1968, in Cleveland, Ohio.

The dates (July 4, 1968) and places (Cleveland, Ohio) are juxtaposed, and commas are needed because the juxtaposed items are clearly different from each other. This applies to countries as well as states: “Asilah, Morocco, is beautiful this time of year.”

Practice

The commas have been removed from some of the following sentences. Re-type the ones that aren’t standardized, adding the commas back in.

  1. Sergi Sousa the top-ranked shoe designer in Rhode Island is going to be at the party tonight.
  2. Sergi only wears shoes that he created himself.
  3. Nevertheless he is courteous about the footwear choices of everyone he meets.
  4. He was born in Barcelona Spain on April 19 1987.

Coordinating Conjunctions: FANBOYS

We also discuss coordinating conjunctions in the Grammar Module of INTD 106. These are words that join two words or phrases of equal importance. The mnemonic FANBOYS helps us remember the seven most common: for, and, nor, but, or, yet, and so.

When these conjunctions join two words or phrases, no comma is necessary (for more than two, take a look at “Commas in Lists” just below):

  • Minh turned off the lights but left the door unlocked.
    • “Minh turned off the lights” is a complete phrase; “left the door unlocked” is not. No comma is required before but.
  • Danny studied the lifespan of rhinoceroses in their native Kenya and the lifespan of rhinoceroses in captivity.
    • “Danny studied the lifespan of rhinoceroses in their native Kenya” is a complete idea; “the lifespan of rhinoceroses in captivity” is not. No comma is required before and.

When these conjunctions are used to join two complete ideas, however, a comma is required:

  • We could write this as two separate sentences, but we’ve chosen to join them together here.
    • Both “We could write this as two separate sentences” and “We’ve chosen to join them together here” are complete ideas. A comma is required before the but.

Practice

The commas have been removed from some of the following sentences. Re-type the ones that aren’t standardized, adding the commas back in.

  1. Aamir and Tyesha went on a trip to California.
  2. Aamir was nervous but Tyesha was excited.
  3. They had been to East Coast before but never to the West.
  4. Aamir became less nervous after he looked up a few tourist guides and journals online.
  5. When they came home Tyesha had not enjoyed herself but Aamir had.

Commas in Lists

The serial comma is used to separate adjacent items—different items with equal importance—when there are three or more. This is so the reader can consider each item individually. Here are a few examples:

  • Weathering may extend only a few centimeters beyond the zone in fresh granite, metamorphic rocks, sandstone, shale, and other rocks.
  • This approach increases homogeneity, reduces the heating time, and creates a more uniform microstructure.

In the first sentence, the commas are important because each item presented is distinctly different from its adjacent item. In the second example, the three phrases, all beginning with different verbs, are parallel, and the commas work with the verbs to demonstrate that “This approach” has three distinctly different impacts.

The Serial Comma (a.k.a the Oxford Comma)

Perhaps one of the most hotly contested comma conventions is the case of the serial comma or the Oxford comma. MLA style (as well as APA and Chicago) requires the use of the serial comma—AP style highly recommends leaving it out. But what is the serial comma?

The serial comma is the comma before the conjunction (and, or, and nor) in a series involving a parallel list of three or more things. For example, “I am industrious, resourceful, and loyal.” The serial comma can provide clarity in certain situations. For example, if the and is part of a series of three or more phrases (groups of words) as opposed to single words:

Medical histories taken about each subject included smoking history, frequency of exercise, current height and weight, and recent weight gain.

The serial comma can also prevent the end of a series from appearing to be a parenthetical:

I’d like to thank my sisters, Beyoncé and Rihanna.

Without the serial comma, it may appear that the speaker is thanking their two sisters, who are named Beyoncé and Rihanna (which could be possible, but isn’t true in this case). By adding the serial comma, it becomes clear that the speaker is thanking their sisters, as well as the two famous singers: “I’d like to thank my sisters, Beyoncé, and Rihanna.”

By always using a comma before the and in any series of three or more, you honor the distinctions between each of the separated items, and you avoid any potential reader confusion.

Note: Some professors and many journals prefer to leave out the serial comma. For the journals, it is literally cheaper to print fewer commas. Because of this, the serial comma is not recommended in AP style. When clarity, not finances, is your concern, we recommend you employ the serial comma.

Practice

The commas have been removed from the following sentences. Re-type them, adding the standardized commas back in.

  1. Ava’s favorite meals are cauliflower soup steak and eggs lasagna and chicken parmigiana.
  2. Victor tried to make dinner for her. Unfortunately his skills are mostly limited to eating buying or serving food.
  3. Victor and Ava decided to choose a restaurant and go out to eat.

Comma Overuse

Perhaps the best way to troubleshoot your particular comma problems is to identify and understand the patterns of your choices. We tend to make the same mistakes over and over again; in fact, many writers develop the unfortunate habit of automatically putting commas into slots such as these:

  • between the subject and verb of a sentence
  • after any number
  • before any preposition
  • before or after any conjunction

Just as it is common for someone to have to look up the same tricky word dozens of times before committing its proper spelling or use to memory, you may need to reference comma conventions multiple times before they feel natural to use. A great place to start is by reminding yourself of the comma’s basic function as a separator and justifying the separation of elements. Taking time over commas in short writing assignments or the self-checks in INTD 106 is an opportunity for breaking old habits and learning new ones before you launch into the rest of your career at Geneseo and beyond.

Practice

Read the following sentences. How many of them have unnecessary commas? Type your standardized sentences in the text frame below.

  1. The bushings, must be adjusted weekly, to ensure that the motor is not damaged.
  2. Other manufactured chemicals that also contain bromine are superior for extinguishing fires in situations where people, and electronics are likely to be present.
  3. The price of platinum will rise, or fall depending on several distinct factors.