Rules for Comma Usage - When to Use Comma

The general rule to follow with regard to the comma usage is to use commas mainly for the purpose of preventing confusion, which would result if words, phrases, or clauses were not so separated. This rule has exceptions, and it should be supplemented by another rule, namely, that the commas should be used as sparingly as possible. In other words, the comma marks a short pause or breathing spell such as is taken naturally by a speaker or writer. Too many commas produce a choppy effect. Too few make the words run together in a confusing fashion.

A comma should always be used to mark off certain words or phrases such as "however," in a sentence like this: "No one, however, would do such a foolish thing."

Commas are also used to separate adjectives or adverbs in a series, as for example: "Keen, cold, driving winds and a cold, wet rain." It should be noted that there is no comma after either "driving" or "wet" for the reason that there is no need of a pause between the last adjective in such a series and the noun, which it modifies. But there is need of a comma between the other adjectives for the reason that without such a pause as is indicated by a comma, the words would "pile up" on each other and confusion would follow.

A comma is generally used to separate a short clause from the rest of the sentence, but this is not a hard and fast rule. For example, take this sentence: "We are at the dawn of an era in education which promises happiness and prosperity to all." Half a century ago many good writers would have placed a comma after "education." But the modern writer would not place a comma here because the meaning is clear without it. In this sentence, however, the case is different:  We are at the dawn of an era in education which, according to the opinion of the best informed educators, holds promises of happiness and prosperity to all." Here the omission of the commas after "which" and "education" would or perhaps might result in misunderstanding. Hence it is good punctuation to use them.

The general rules for comma usage can serve to assist the apprentice writer to teach himself how to use the comma. The beginner in writing can advance himself in no way faster than to observe how good writers punctuate and to try to figure out why they punctuate as they do. And in making this study it should always be remembered that there are fads and fashions in punctuation as in everything else, so that it is not surprising to find writers using punctuation marks, such as the comma, in quite a different way from the writers of a century or more ago. Use of punctuation depends very much on the use of language, on shades of meaning, and not very much on hard and fast rules. Software like punctuation software can be used to correct punctuation errors in writing and for clarity of messages. For more information on punctuation checker software, please visit grammar and punctuation software.