Many writers have misconceptions about when and how commas should be used. Common myths are given below.
How to Know When You Need a Comma
Long sentences need a comma. True or false? Some very long sentences may be grammatically correct without any commas. The length of a sentence does not determine whether a comma is needed. However, long sentences do require more finesse of writing and a better understanding of the rules of grammar and punctuation in general.
Writers should add a comma wherever they might pause if reading aloud. True or false? Different readers pause or breathe in different places, so where a reader pauses or breathes does not always indicate where a comma belongs. However, there are commas called pausals that do tend to follow natural pauses. These usually follow dates, i.e. In 1985, it was thought… etc.
Most of the time, commas belong in very predictable places in a sentence.
Where to Put Commas: FANBOYS and Comma Splices
Some of the most common errors occur when punctuating coordinate clauses or when conjunctions are used. FANBOYS is the acronym given to the conjunctions for, and, nor, but, or, yet and so. These words are used to join two clauses together in a sentence. When appropriate conjunctions are omitted a comma splice occurs (where two independent sentences are joined only by a comma).
Take for example: It began to rain. It was a still beautiful day. (Correct, but staccato sentences are usually only suited to fiction.)
It began to rain, but it was still a beautiful day. (Correct — fanboy use joins two clauses.)
It began to rain, it was still a beautiful day. (Incorrect — comma splice).
Commas After Adverbial Clauses
Adverbs often end in –ly and usually modify verbs, adjectives or other adverbs. For instance, “He (pronoun) walked (verb) quickly (adverb) to (preposition) the (definite article) door (noun)”. Traditionally, a comma is placed after an adverb or adverbial clause at the start of a sentence, such as: Lastly, I would like to thank you all.
Unfortunately, they lost the game.
Apparently, Justin was unwell.
He arrived late, attracting the attention of the professor.
In 1985, ra-ra skirts were all the rage.
Suddenly, the door flew open.
Don't Put Commas Before Conjunctive Adverbs
Words like however, nevertheless, furthermore, therefore, subsequently and consequently are conjunctive adverbs. Commas should not be placed before these adverbs, which require a semi-colon (or a full stop), but are generally placed after them, preceding the following clause. E.g. Its expiry date had passed; nevertheless we ate it. (You may choose to do that; however, I wouldn’t advise it!). There are a few exceptions, such as: I noticed, however, that eating the expired cheese made them all sick.
Omitting Commas Can be a "Style" of Writing
Comma use is not always so predictable, however, particularly in literary fiction where the omission of commas can help create a character who might be loquacious or can help create a "stream of consciousness" style of writing. The trend in recent years is to minimize comma usage in general, particularly in strings of adjectives that premodify a noun, e.g. The big black scary, scaly monster; rather than "the big, black, scary and scaly monster".
Is an Oxford Comma, or List Comma, Necessary?
Oxford commas, so named because they are suggested by the Oxford Style Manual, are sometimes necessary and sometimes unnecessary. They are also known as "list commas" because they precede "and" in a list of items, take: "We ate cheese, salami, gherkins, and pickles". Some publishing houses suggest that the Oxford comma is unnecessary and should never be used, but it can serve a useful purpose when the last item of a list is markedly different from the others. Consider, "Children will need paper, pencils, scissors, glue, and a lot of patience. Often an em dash to separate the last list item will also work just as well.
Overusing Commas
Overuse of commas can be just as detrimental to a piece of writing as under using commas. More than five commas in any one sentence generally means the sentence needs revision. While some long sentences can still be correctly punctuated with a lot of commas, most readers benefit from a combination of short, medium-length and longer sentences. Sentences of more than sixty words usually require a good grasp of grammar and punctuation in order to work.
Another important point is that writers benefit from having a distinct writing voice and style, so establishing comma rules for lists and adjective strings, and sticking to it, will help writers remain consistent.
