The New York Times has been running a series called "Draft" in its Opinionator blog at the Opinion pages. Today, Ben Yagoda posted an entry, The Most Comma Mistakes, the second part of a series on the use of the comma in writing, and it's full of useful information.
This is really an informational post to let you know about this resource. If you've ever heard the phrase "commas at random" you know all about this, and the article points out some of the most common errors we all make with it. To wit:
Identification Crisis: The syntactical situation I’m talking about is identifier-name. The basic idea is that if the name (in the above example, “Jessie”) is the only thing in the world described by the identifier (“my oldest friend”), use a comma before the name (and after it as well, unless you’ve come to the end of the sentence). If not, don’t use any commas.
With examples.
The Case of the Missing Comma: A related issue is the epidemic of missing commas after parenthetical phrases or appositives — that is, self-enclosed material that’s within a sentence, but not essential to its meaning.
The parenthesis/comma conundrum. With examples.
Splice Girls, and Boys: “Comma splice” is a term used for the linking of two independent clauses — that is, grammatical units that contain a subject and a verb and could stand alone as sentences — with a comma.
This is exactly the "commas at random" situation. With many examples, including a nice quotation from Samuel Beckett.
For serious in-depth consideration of these issues, you really can't do better than the Purdue University Online Writing Lab. This is the resource I used when, as a graduate student, I worked at the Claremont Graduate University Writing Lab.
No snark, nothing to embed, just this.