Semi-colons, bitches

Not so long ago, we talked about colons. The whole wide world seems to confuse colons and semi-colons, but as we are about to see, the semi-colon is nothing like the colon. They are, in effect, unconfusable. Isn't that a relief?

Semi-colons are very simple. Think of a semi-colon as being a half full-stop.

The alligator ate the dog. He was soon sated.

The alligator ate the dog; he was soon sated.

Both are correct. Here's the thing: semi-colon usage is most frequently a stylistic choice. The only rule is that the two phrases joined by the semi-colon must also be able to be separated by a stop; the two phrases (like these ones) must be able to stand alone as independent sentences.

So why would you use a semi-colon?

The first option above is very definite. Some might say that rhythmically it's a bit boring, being, as it is, the presentation of two separate facts in two separate, similarly constructed sentences. Yawn.

The second option has more flow. The sating is more closely tied to the eating. The semi-colon joins these two facts more tightly than does the stop. The semi-colon joins what the full-stop puts asunder.

That may sound high-falutin' (or biblical) but it actually makes a considerable difference in real-life prose:

There is a paved area beside the door, and here his breath forms small clouds in the chill air. All is silent; even the hens have housed themselves. The dying light seeps, luminous, over the dark green hillside to his right.

You, of course, know why a colon would be incorrect in all these cases. Try dropping "ta-daaa!" in where those semi-colons appear and all you have is a mess. The housed hens, for example, are not precipitated by the silence. A colon does not work where a semi-colon is needed. A dash could work there (All is silent—even the hens have housed themselves) but a colon would be an alarming choice.

As an aside, you can also use a semi-colon to separate items in a list where those items themselves contain comma-separated lists:

Having consumed the dog, the alligator proceeded to ingest a rosemary bush; three kittens named Lisle, Betty, and Alan; six hard-boiled eggs; and a plate of roast beef.

See? I told you semi-colons were simple.