Punctuation Pitfalls – The Comma, Part 3

Commas Used with Parenthetical Expressions.

I had no intention of staying away so long. Computer problems brought on my absence, then blogging about punctuation slid toward the bottom of the list of priorities as I scrambled to catch up.

I think that’s as it should be. Good punctuation does not make good writing. It only makes good writing clearer.

I want to pick up the instruction on comma use with one of the easier directives—easier, that is, until we get to the “except” part of the rule.

But here’s the essence: Use commas to separate non-essentials from the rest of the sentence. (The grammatical term is “parenthetical elements”). What do I mean by “non-essentials”? Interjections, like oh and indeed; transitions like however and therefore; and descriptive phrases like … well, I’ll need to give an example.

if not the most oft-repeated

In this sentence, if not the most oft-repeated does not add essential meaning. If the writer were to remove it, the sentence would still be complete and clear. Think of these kinds of phrases as bonus material—helpful, informative, but not part of the basic package.

I mentioned an exception, but that isn’t quite accurate. On rare occasions interjections or transitions may be essential, in which case, they do not fall under this non-essentials directive.

That may seem confusing if a writer is thinking that some words, by virtue of their part of speech, must be separated by commas from the rest of the sentence. However, if a person thinks of the function of the word in a particular sentence, there’s a bit of a judgment call, which can make comma use a little iffy.

Here’s an example of a necessary transition:

Two workers didn’t finish and therefore received less pay.

The transition therefore serves as a necessary tie between the cause and the outcome and therefore does not require commas. (Just as the therefore in this sentence does not. 😀 )

Fortunately, as I stated above, these occasions are not frequent.

Probably the most helpful piece of information to remember is this from Chicago Manual of Style: “Commas set off [separate from the rest of the sentence] parenthetical elements if a slight break is intended.” (CMS, 6.30)

Now every writer should be able to identify the places he intends to create a slight break, shouldn’t he? 😉