About Comma Usage
Writers of all levels of skill have struggled for years with the problem of where to place or where not to place the comma. Recently Ramsay MacMullen, emeritus professor of history and classics at Yale University, examined the roles of punctuation and voice in expository writing in Literary Imaginations, a new journal of the Association of Literary Scholars and Critics. MacMullen states that there have, historically, been two main schools of thought on the role of punctuation.
The first, and oldest, dictates that the marks should stand for how a speaker would articulate the words, and at what pace. In other words, Mr. MacMullen writes, "Our thinking about how we write should properly begin with how we speak."
The later, early-20th-century, view suggests that punctuation should offer only visual and grammatical guidance. For as Mr. MacMullen summarizes, "Writing is just that, a visual thing; and it is the logic of grammar that writers must invoke to help them out with commas and so on, not how they speak."
The 70's challenged that stern notion, and once again, Mr. MacMullen notes, "Speech recovered its primacy over writing." No less a writer than Eudora Welty wrote, "Ever since I was first read to, then started reading to myself, there has never been a line I didn't hear. As my eyes followed the sentence, a voice was saying it silently to me. . . . I have supposed, but never found out, that this is the case with all readers -- to read as listeners -- and with all writers, to write as listeners." Indeed.
Physiology reveals that there is an "inner ear": Speech organs are stimulated during reading, or what Mr. MacMullen terms "the mind's eye, the nerves and muscles of gesticulation." Science has proven what 17th-century literary scholars believed: "Readers inwardly turn writing into speech, so far as they are able."
The current wisdom holds that how we would speak the sentence should guide us on where to place the comma. This theory, however, does not always work in practice. We tend to put in either too many commas or not enough commas. To clear up the confusion, we will have to turn to rules. Happily that is not a daunting task as five rules suggest where over 90% of the commas should go.
When a coordinating conjunction – and, but, or, nor, for, so, yet -- connects two or more independent clauses – word groups that could stand alone as separate sentences – a comma must precede the coordinating conjunction.
Commas are used to tell readers that the introductory information is completed and that the main part of the sentence is about to begin. Commas are used if
A subordinate clause has both a subject and verb but cannot stand by itself as a sentence because it is preceded by a subordinator such as because, since, when, while, etc.
A phrase can be of several types and purposes, but what distinguishes a phrase from a clause is that a phrase does not contain both a subject and a verb.
A transitional expression serves as a bridge between sentences.
These interrupting elements can be nonrestrictive elements.
A nonrestrictive element describes a noun or pronoun whose meaning has already been clearly defined or limited. Because it contains nonessential or parenthetical information, a nonrestrictive element is set off with commas.
Parenthetical expressions provide supplemental comments or information but interrupt the flow of a sentence or appear as afterthoughts.
The interruption elements can be nouns of direct address, interrogative tags, or mild interjections
When you list three or more items, separate them with commas.
When two more adjectives each modify a noun separately, the adjectives need to be separated by commas.