Hai! I am going to rant about commas today, because comma usage popped up in a comment thread earlier and I have quite the pet peeve on for errant commas. I absolutely cannot stand them, largely because I correct/remove so, so many of them in the course of my job. The comma splice nightmares I could show you....* shudder *
So anyhoo, since commas seem to be the most confounding of the punctuation marks, I thought I'd make an attempt to clarify their usage. For anyone who's interested, the nerdy goodness is below the squiggeldy-doo.
In contemplating the confounding nature of the comma, my initial reaction is "Yet another reason to avoid their use!" I mean, I don't hate them that much, but it actually is true that when it comes to commas, less is more and erring on the side of comma-stingy is the best strategy. Basically, if you're not sure it needs a comma, don't use one.
Aaaaahhhh, but how to be sure? That's the whole comma conundrum, no? Rather than getting bogged down in the minutia regarding commas and their usage, let's take a minute to contemplate the purpose of commas instead. I believe thinking of them in broader terms really adds clarity when trying to grasp all the specifics of the rules.
So, there are two main points to always, always keep in mind when it comes to commas. The first one is that the purpose of commas is not to indicate emphasis. I repeat:
The purpose of commas is not to indicate emphasis.
The second thing to always remember is what the purpose of commas
is. The function of commas is to define the relationships between parts of a sentence. Didja take a minute with all of that? Okay. Here is a sentence that hopefully demonstrates the point:
For the next three quarters, we will incur incremental one-time capital spending associated with consolidation of facilities, both in Northern and Southern regions, the sum total of which will equal roughly $5 million.
Compare that with this:
For the next three quarters, we will incur incremental one-time capital spending associated with consolidation of facilities, the sum total of which will equal roughly $5 million.
Notice how the sentence reads just fine without the part about regions? That's because it was interesting, but not essential to the sentence, which is why it was offset by commas. Notice how the comma after "facilities" remained? That's because "the sum total..." clause is not a stand-alone sentence; it needs to be attached to something. In this case, it is a descriptor attached to the sentence where the thing it's defining, the one-time capital spending, lives.
But we are skirting the edge of nitty-gritty details here, so I will stop with the examples and just reiterate that the function of commas is to indicate how the words in a sentence are related. Think of them as structural framework of a sort. Here it is, put a slightly different way:
Commas help your reader figure out which words go together in a sentence and which parts of your sentences are most important.
I could have chosen any of a number of grammar websites for such a quote, but this one got extra points with me for using the term "introductory bits" and for dispelling a particular comma myth that drives me especially batty. Apparently, it is not uncommon that people are taught commas are to be used to indicate a pause. It's a truly ghastly thought for those of a grammarian bent. I mean, look at how slow and measured Obama's speech is. If the "pause" standard were applied, his speech transcripts would easily be 1/3 commas! Of course, nothing illustrates
this point better than The Shatner Comma.
"Professor friend o mine is against losing the Oxford comma, but wishes his students would lose the Shatner comma. You, know, what, he means."
The Shatner comma! That, is, you, know, a really, fantastic, idea.
See, the problem people have with the Oxford comma is that it puts a pause where some think one doesn't belong. The idea is that "I went to the market to get triple sec, limes and tequila" is better, or more modern, than "I went to the market to get triple sec, limes, and tequila." And the Shatner comma? It, does, nothing, but, put, pauses, where, they, do, not, belong.
Now to be fair, it is actually true that commas indicate pauses, but here's the thing about that: it is absolutely a one-way street. Commas on the written page let someone
reading the page aloud know that he/she should pause slightly
for the sake of clarity. It does not work in reverse: pauses in speech or thought do not necessitate the use of a comma when those words/thoughts are transcribed.
I put "for the sake of clarity" in italics because it underscores the role of commas as defining relationships between words. Their purpose is to add clarity; if you keep this idea in mind when wrangling over the use of commas, it all makes a lot more sense. Commas are all about structure, relationships, and clarity.
As I said, you can find heaps of grammar websites expounding on specifically when and when not to use commas. I don't see this topic addressed much, though, so I will go ahead and include it here. This is more an observation, or a rule-like object, than an actual rule; it's just something I've encountered a lot.
Sometimes, "which" needs a comma; sometimes, it doesn't.
Which movie are you seeing?
That one's obvious. Where it gets tricky is when "which" is used in a dependent clause and/or as a substitute for "that."
Comma yes: Our operating cash flow was $2.8 million, which we had forecast would be down.
Comma no: As you may have seen, we now have a budget in place for 2012 which promises strong growth in widgets.
In the first example, "which" kicks off a non-restrictive clause, so it needs a comma. In the second example, "which" is used in place of "that" and does not need a comma. Basically, if you can substitute "that" for "which" and the sentence still works, you should really just go ahead and substitute "that" for "which" and be done with it. But if a document has to be verbatim and "which" has been used in place of "that," you needn't use a comma.
Without further ado, five main rules for comma usage:
Use a comma to separate the elements in a series (three or more things), including the last two.
Use a comma + a little conjunction (and, but, for, nor, yet, or, so) to connect two independent clauses.
Use a comma to set off introductory bits.
Use a comma to set off parenthetical elements.
Use a comma to separate coordinate adjectives.
Clear as mud, eh? I hope this diary has helped at least a little!
update: It was suggested that we should have a dkos group for Cranky Grammarians. Alea iacta est. Leave a reply at this comment if you'd like to join it!