To run-on, or not to run-on

I'm tempted to say something about whether tis nobler in the mind to suffer the slings and arrows of outrageous punctuation, but then I'd want to turn the rest of Hamlet's speech into a musing on grammar, and I lack the mental energy to summon the whole text from the dark corners of my memory. Ay, there's the rub. So instead, we'll talk about a grammar question posed to me on twitter.

 Are run-ons okay nowadays? I've run across so many manuscripts without commas between two indie clauses and a conjunction.

I've noticed this, too. I also have been spotting more run-ons in published manuscripts -- technically, what I've seen are spliced sentences, which are a species of run-on. Before we talk about whether and why they might be okay, let's do a quick refresher on run-ons.

A simple declarative sentence is composed of a subject and predicate. The subject is a noun, and the predicate is a verb and perhaps an object.

The dog eats.
article- subject noun-verb.

The dog eats its dinner.
article-subject noun-verb-possessive pronoun-object noun.

This unit, the subject noun and the verb showing its action, is the basic meaning unit that creates a sentence. We can dress it up with dependent clauses and phrases, or we can shift it around into an interrogative or imperative form. Nevertheless, our basic meaning unit, the simple sentence, will consist of a subject and verb working together as a complete idea.

There are two basic categories of ways that this basic meaning unit can be gummed up. The first category, fragments, results when the words don't add up to a real, complete sentence, but are only part of a sentence. This category has become more or less accepted in casual forms of writing, including much genre fiction.  The second catogory, run-ons, results when too many meaning units are jammed together without the proper connective tissue, and though these are popping up more frequently, they're less acceptable than fragments.

Why is this? Probably because our mind can grasp the meaning of a fragment a little more easily than it can grasp the meaning in a run-on. Look at this, for example:

The dog eats the cat paws its dinner.

What is the dog eating? It's impossible to know for certain, because as written, this could either be a single sentence or two sentences jammed together.

Add a comma after paws, and its dinner becomes an appositive.

The dog eats the cat paws, its dinner.

Add a period after eats, and we have two complete sentences comparing the behavior of two animals.

The dog eats. The cat paws its dinner.

Punctuation tells our eyes how to bunch the words together so that they make sense -- as Alicia says, they are like traffic cops inside the sentences. Typically, we use end marks (periods, exclamation points, question marks) to indicate the end of a basic meaning unit, the sentence. But sometimes basic meaning units are strongly related enough that we want to contain them within a single sentence. In that case, we use either a semicolon (which is a weak period) or a conjunction (and, or, but, nor, for, yet, so).

The dog eats; the cat paws its dinner.
The dog eats, but the cat paws its dinner.

Usually, it's better to use a conjunction rather than a semicolon. Why? Because a semicolon tells you nothing about the nature of the joining. Compare:

The dog eats, but the cat paws its dinner.
The dog eats, so the cat paws its dinner.

Changing the conjunction changes the way the basic meaning units relate to each other. A semicolon would not add a shade of meaning there, but it would make the tone more formal, so many writers eschew them. I suspect this is why we now see so many writers using spliced sentences, in fact. I suspect they would ordinarily reach for a semicolon, but instead use a comma because they know editors sometimes say, "Gack! Ptooey!" when they see semicolons.

The dog eats, the cat paws its dinner.

Now the clarity issue is solved. We know that the dog is not dining on cat paws. But it has been solved by use of a spliced sentence, which is a type of run-on. Technically, a spliced sentence is what we get when we join two basic meaning units with a comma and no conjunction. I suspect we're seeing more of these in genre fiction because they do have a very casual feeling suitable for genre fiction, and because there's no problem with clarity. Personally, I would still fix that sentence in edits, but I'm willing to tolerate a little bit of splicing in my reading material as long as clarity is not damaged.

What do you think? Do you find run-ons annoying, or will you let them slide on occasion?

Theresa