In a Quandary over Commas?

Does this bring back memories of composition class?

How can one small punctuation mark (,) cause such a big headache?  Admit it!  Do you feel completely secure when deciding whether to place or omit commas in your writing?  You are not alone.

The dilemma of comma placement was recently brought to my attention because a friend of mine, a former English teacher, offered to proof a manuscript I am working on. She did a very thorough job, and I very much appreciated her careful editing skills.  However, I noticed immediately that we hold different opinions regarding use of commas. Are commas governed by hard and fast rules, or is there some wiggle room in their usage?  I needed to find out quickly.

I pulled Steven Pinker's The Sense of Style:  The Thinking Person's Guide to Writing in the 21st Century off the shelf of my Linguistics reference books.  The information on the front book flap advises readers that "...they must negotiate the rules of correct usage, distinguishing the rules that enhance clarity and grace from myths and superstitions...."  Maybe the section on usage would provide me with ammunition in my campaign against what I consider to be excessive use of commas. The index listed ten pages, 285-294, devoted to comma usage.  The topic was obviously not a simple one!

Pinker explains that, in the past, decisions about comma placement were made to indicate a slight pause in pronunciation.  More recent rules are based both on sound and sentence structure. He observes that instructors of English composition often have to deal with both comma overuse and under use.  Comma overuse occurs when the writer incorrectly sets off elements that belong together, such as the subject and verb.  Comma under use, the opposite problem, occurs when the writer fails to set off supplementary information.  Take for example,  "The lot next to mine which is huge is still undeveloped."  If the writer is adding the phrase "which is huge" as non-essential information, the sentence should read, "The lot next to mine, which is huge, is still underdeveloped."

I get the main idea here, which is that essential information should not be separated by a comma, and that extra information should be set off by commas.  What I am saying is the decision is not always easy. For example, when the supplementary information is short, and you don't want the reader to pause, then a reasonable decision would be to omit the comma, as in "Finally this comma discussion has ended" (no comma after "finally").  Steven Pinker identifies this style as "light" or "open" punctuation.

A more definite rule that Pinker offers is the admonition against the dreaded comma splice, which is when a comma is used to join two sentences that can stand on their own.

Of course, a writer has to be able to recognize a complete sentence in order to follow the rule. Pinker gives several simple alternatives for correcting the comma splice.

Another major decision regarding commas, according to Pinker, is the serial comma, also known as the Oxford comma. A major function of commas is to separate items in a list. Compare "Please bring home cheese, wine and bread and butter pickles" (no comma before third item) to "Please bring home cheese, wine, and bread and butter pickles" (additional comma).  The Oxford comma makes the second sentence easier to understand.  Pinker recommends its use.

Wow!  Some people are very serious about the Oxford comma!

My takeaway from a quick investigation of comma use and misuse is that some rules are non-negotiable, like the comma splice, while other rules require attention to elements such as the flow of the sentence, the structure of the sentence,  and meaning of the sentence.  Now I'm not sure if I have gotten myself out of a quandary over commas or become more neurotic about using correct punctuation.  How about you?