Here’s a rule:

Semicolons separate independent clauses.
Commas separate parts of a sentence.

An independent clause is a sentence that happens to be attached to another sentence. An independent clause has its own subject and verb, and could stand alone. In fact, the decision as to whether to make something a stand-alone sentence or an independent clause is often a matter of preference—the choice can affect the tone of the writing, but both choices are grammatical.

Here’s a sentence that gets it wrong:

A transition is a one-way link, if an issue moves back and forth between two statuses; two transitions should be created.

https://www.tutorialspoint.com/jira/jira_quick_guide.htm

That comma should be a semicolon. Even a period would work. And that semicolon should be a comma. The “if…” part goes with what follows; it’s a dependent clause (called an apodosis, if you want to know the technical term). So here’s what the sentence should look like:

A transition is a one-way link; if an issue moves back and forth between two statuses, two transitions should be created.

Feels better now, doesn’t it?

Subscribe to this blog's RSS feed

The comic is about grammar, so go ahead; read it and chuckle. My lesson, though, is in the last panel. 

We call it direct address when you name the person (or persons—or readers, shall we say) whom you are writing to. Sometimes I start a post with, “Our lesson for today, class, is…” That’s direct address.

Here’s the rule, in case the rule isn’t already obvious:

Separate direct address from the rest of the sentence with commas.

Of course, the plural, “commas,” applies only if the direct address is inside the sentence. If it’s the first or last word, you need only one comma. duh.

PS—wouldn’t you know, the comic repeated the same joke a week later:

Normally, a comma indicates a small pause of some kind in a sentence. And using a “from-to” construction indicates a range. I just ran into a usage where a comma changed the type of range in a from-to construction. It’s a headline to an article about a hockey team:

From underdogs, to National Champions

Without the comma, the headline might be above an article listing teams starting with low skill and ending with the top-of-the line team. But with the comma, the meaning changes to a passage of time for one team.

Interesting.

He makes a good point about the comma, though. The construction with the comma is called “direct address.” Without the comma, it’s “direct object.”

Got if off of Facebook, and now I can’t find it to give credit.

Commas are useful punctuation marks. They serve to separate, and they show a weaker separation than semicolons, which are weaker than periods. We’re familiar with commas separating the parts of compound sentences and the parts of lists. Commas are used for another kind of separation, and I’m not sure what to call it. Here’s part of a sentence:

 “If we do end up finding something that’s good,

I’ll stop there for a moment. What’s good here? It looks like something is good, right? But when you see the rest of the sentence, you discover that it’s the finding that’s good!

 “If we do end up finding something that’s good, but even if we don’t find anything, that works as well,” says Marco Bortoletto, one of the archaeologists on the team.

We should have a comma after “something” so we can tell that what’s good isn’t the something. That’s the separation I’m writing about. Beyond representing a pause in spoken language, I’m not sure what to call it. Sorry.

So here’s how the sentence should be written:

 “If we do end up finding something, that’s good; but even if we don’t find anything, that works as well,” says Marco Bortoletto, one of the archaeologists on the team.

Notice that I changed the comma after “but” to a semicolon. It’s a good idea to use a semicolon to separate the parts of a compound sentence if the parts have their own commas. But that’s another lesson.