You can get by in your writing without ever using a semicolon. There is always a way around it. If you write, you will eventually have to use a period. And if you know what’s good for you, you will put some commas in there too. Question marks are sometimes necessary as well. And quotation marks. And colons are often called for. But semicolons? They can be totally avoided by alternatives and rewriting. But they are so nice to use sometimes for variety—and necessity.
The first thing to do is to disassociate the semicolon from the colon. They don’t have much in common at all and are definitely NOT ever interchangeable. The semicolon has much more in common with the comma, and is kind of a supercomma, if you will. Colons generally announce that something is coming: they introduce lists, either vertical or horizontal, or maybe a long quote. Semicolons don’t do that.
So enough beating around the bush, you say. What do I use the semicolon for?
The semicolon really has only two uses:
1. It is used to separate two (or more) closely related sentences.
2. It is used where a comma would be used (to separate items in a series, or to connect two sentences where there is a conjunction like and) if there are already too many commas, and things are hard to read.
The first use is easy. You have two sentences. You can separate them with a period. Or, you can separate them with a comma IF YOU ARE USING A CONJUNCTION. Or, if they are closely related, you can use a semicolon.
I am taking the train to New York. My brother is flying.
I am taking the train to New York, but my brother is flying.
I am taking the train to New York; my brother is flying.
See? Easy! Just remember to use a lowercase letter to begin the sentence after the semicolon, and don’t use a conjunction.
If the sentences are not closely related, stick to a period.
The second use for a semicolon can be worked around by rewriting if you want to avoid using semicolons. Here are a couple of samples of using semicolons as “super commas.” The first is in a series. Generally, you separate the items in a series with commas, but if some or all of the items already have commas, your sentence can be confusing:
I went to New York with my brother, Jim, Alice, my cousin, Beth, my mother, and my grandmother.
Well, that is a little confusing. It is impossible to tell who is who and how many people are going with you. Here is the same sentence cleared up with semicolons:
I went to New York with my brother; Jim; Alice, my cousin; Beth, my mother; and my grandmother.
Now you know there are five people going with you. Jim and your brother are not the same person. However, Alice is your cousin, and Beth is your mother. So you are separating the big items (yes, even before the last item) with semicolons because the individual items already have commas in them.
Here is an example of a complicated compound sentence that could use semicolons:
My company’s offices are in Bangor, Maine, Manchester, New Hampshire, and Queens, New York, and the other company’s offices are in Hoboken, New Jersey, Boston, Massachusetts, and Baltimore, Maryland.
Understandable if you know some geography, but so many commas!
My company’s offices are in Bangor, Maine; Manchester, New Hampshire; and Queens, New York; and the other company’s offices are in Hoboken, New Jersey; Boston, Massachusetts; and Baltimore, Maryland. (In this case, you can leave the conjunction and, or you can leave it out.)
One more example to sell you on the use of semicolons:
I packed the following items: two pair of pants, brown and blue, three shirts, three pair of black shoes, gray, black, and brown socks, and striped pajamas. (Forget the fact that nothing matches!)
Let’s use semicolons:
I packed the following items: two pair of pants, brown and blue; three shirts; three pair of black shoes; gray, black, and brown socks; and striped pajamas.
You can hear the story of the semicolon on YouTube