Monday, April 21, 2008

The two most common comma mistakes I see good writers make

As hard as it will be for many of my colleagues to believe, I actually know a couple of grammar rules and even advocate that people follow them.

I just finished a couple of weeks of peer editing and saw good writers making similar mistakes, the same mistakes I see good writers make a lot. The problem, I think, is that our brains know the rules but our fingers ignore them under the pressure of deadlines or when the muse is inspiring us with good content. But for what it is worth, here are the two comma errors I see most often (so if you are guilty of either or both of them, you are in good company).

Punctuating compound predicates as if they were compound sentences

A compound sentence has two complete clauses joined by a conjunction. A comma comes before the conjunction. Example: John wrote the user guide, and Mary edited the installation guide. Two subjects each with their own verb.

A compound predicate has only one subject but two verbs. No comma is used. Example: John wrote the user guide and edited the installation guide. If you absolutely long for a comma in the second example, you merely have to add a subject as in: John wrote the user guide, and he edited the installation guide.

Good writers usually make this mistake when the predicate elements are long, as in: John wrote the user guide that went with the latest version of the TurboPro Archiver, and edited the installation guide that went with the X-Level Wiki Mapper for Linux.

Long, but still a compound predicate and no comma.

Separating a two-item list with a comma

A two-item list does not take a comma. You would never write: You can choose option A, or option B. But as in the first error, good writers confuse themselves when choices get wordy: You can assign users to a category based on the permissions you have granted them in Section 10.4, or based on the profiles you establish in Section 14.6.

Long, but still a two-item list and no comma.

What is getting in the way in both examples is long sentences and the mythical comma rule of "use a comma when the reader needs to take a breath."

No such rule. No NEED for such a rule. None of us has written a technical document so compelling that the reader forgot to breathe. In my own case it's as if I breathe without even thinking about it. My lungs suddenly get hungry for air and wooosh; it just happens. I don't think I've ever heard of a situation where a reader was found blue and unconscious with those around him saying, "Oh my god! If only the technical writer had told him to breathe."

At any rate, be mindful that our fingers and this mythical rule are out to put spurious commas into the otherwise well-punctuated prose of even the most seasoned veterans among us. Keep a watchful eye out.


Sarah said...

So THAT's why it's called "deathless prose"!

Mike Hughes said...

well, at least no deaths have been attributed to CDA (Comma Deficit Asphyxiation)

Tom Johnson said...

As much as I admire anyone's desire to improve the grammar on the web and elsewhere, I think you're too conservative in your approach.

In your first rule about not punctuating compound predicates with a comma, this sentence wouldn't be grammatical:

"I ended up redesigning the look and feel of my entire website this weekend amid chaos and numerous family commitments, and then deleted everything."

Sometimes you have an afterthought that's not really part of the compound predicate, but which is attached at the end somewhat like with a dash. In that case, you can insert a comma without having what follows be an independent clause.

In the second example you highlighted, although it may not be something you're condemning, the Microsoft Manual of Style says to write instructions like this:

"Click the File menu, and then select Open."

It's a series of two steps that seem to break the rule you've explained. I write "seems" because one could argue that words are left out, and that I'm really writing,

"[You] click the File menu, and then [you] select Open."

Adding the comma even when there are only two items emphasizes the distinctness of the steps.

What are your thoughts on requiring an independent clause before a colon?

Mike Hughes said...

You're first example can be fixed by saying, "...commitments, and then I deleted..." Adding one character to preserve the correct comma use is a reasonable effort :-)

As for your second example, since each clause is in the imperative mood, pronouns are not required, and I agree with MS, the comma is.

Whether or not you require an independent clause before a colon is a style issue in my mind. I could easily envision a quick start guide that said

Things to remember:

Anonymous said...

In "Punctuating compound predicates as if they were compound sentences," are you not talking about complex sentences rather than compound sentences.

That is, two independent clauses joined by a conjunction take the comma, other wise a dependent clause and an independent one do not.



Mike Hughes said...

A complex sentence has a main clause and a subordinate clause, and the subordinate clause contains a subject and a predicate. A compound predicate has only one subject.
Complex sentence: When Mary finishes the user guide, John edits it.
Compound sentence: John edits the user guides, and Mary writes the online help.
Compound predicate: John edits the user guides and writes the online help.
I see this kind of mistake: John edits the user guides for the TurboPro version 3.1 release, and writes the online help for all the other versions.

That last sentence is a compound predicate punctuated as if it were a compound sentence.