Semicolons and Lists
I'll get this one out of the way because it's the usage I am least often asked about, and it's probably not one that will come up as often in fiction as the main usage we'll be discussing. When you're listing something in a sentence and the individual list items contain commas, you can use semicolons to separate the items in the list so that you don't end up with a sentence that looks like William Shatner dropped all his extra commas in it. For example, if I'm naming places I've lived, I might tell someone, "I've lived in Towson, York, Pittsburgh, and Manchester." No need for a semicolon anywhere in there. But if I want to include the states along with the cities, that automatically adds four commas between each city and state. In that case, I'll separate each list item with a semicolon, and it'll look like this:
I've lived in Towson, Maryland; York, Pennsylvania; Pittsburgh, Pennsylvania; and Manchester, New Hampshire.
If I just list them as Towson, Maryland, York, Pennsylvania, Pittsburgh... etc. it becomes unclear whether I'm saying that I've lived in Towson, and I've lived in Maryland, and I've lived in York, and I've lived in Pennsylvania, and so on.
Independent Clauses, Comma Splices, and Conjunctions
The most basic explanation you've probably heard is that you use a semicolon to join two independent clauses. An independent clause can stand on its own as a complete sentence.
Independent clause: Tears well up behind my eyelids.
Independent clause: I squeeze them tighter so I won't cry.
Correct semicolon use: Tears well up behind my eyelids; I squeeze them tighter so I won't cry.
It sounds easy enough, but I know that many people still falter when it comes to using semicolons. Have you had a critique partner or editor call you out on comma splices? Those occur when you use a comma alone to join two independent clauses, and they are incorrect. You don't want to end up with comma splices any more than you want to incorrectly use a semicolon.
Comma splice error: Tears well up behind my eyelids, I squeeze them tighter so I won't cry.
Another way to join two independent clauses is with a comma and a conjunction. However, you don't use conjunctions when you join clauses with a semicolon. (You can use a semicolon and conjunction with lists as shown above.)
Comma and conjunction (correct): Tears well up behind my eyelids, and I squeeze them tighter so I won't cry.
Semicolon and conjunction (incorrect): Tears well up behind my eyelids; and I squeeze them tighter so I won't cry.
A semicolon can replace a period between sentences, and it can also replace the comma and conjunction between independent clauses. It can replace those, but should it? This is where I think a lot of people falter in their use of semicolons.
A semicolon isn't something you just go tossing into your manuscript between sentences for the sake of variation. There's more to it than that. A semicolon joins two clauses that are closely related; your intended meaning is a vital part of this punctuation choice. This is where the thrill and joy of writing, of crafting worlds and lives and stories practically from thin air, should push aside any disdain you may have for the banality of grammar rules. Personally, I think grammar is pretty rad, but I know most of the people asking me about how to use semicolons don't necessarily share my enthusiasm. It's not a matter of The "rules" say I "can't" use a comma here, because "rules" or whatever. (And I totally hear you using those scare quotes in your mind when you complain about grammar like it's some old curmudgeon yelling at you to get off his lawn. Don't deny it.) A semicolon is an option that allows you, the author, to better convey the meaning of and relationship between the words you've so carefully chosen. The relationship between clauses feels very different when separated with different punctuation. Let's take a look at another example.
Separate sentences: I can still smell him in our bed. I didn’t mind it for the first few days, but tonight it’s unbearable.
Comma and conjunction: I can still smell him in our bed, and I didn’t mind it for the first few days, but tonight it’s unbearable.
Semicolon: I can still smell him in our bed; I didn’t mind it for the first few days, but tonight it’s unbearable.
Using two separate sentences in this example would be perfectly acceptable. Each thought stands on its own grammatically, and there's nothing wrong there. Joining them with a comma and conjunction results in a long, awkward sentence. It doesn't really work because it tries to force a closer relationship between the two sentences than there actually is. There isn't a strong enough correlation to warrant joining the sentences that way. (Compare that to the example in the previous section, where there was a strong enough relationship that using a comma and conjunction would've been a decent choice.)
But the semicolon! Be still, my grammar-loving heart! Because the two sentences are closely linked, a semicolon is a great way to express that connection. As the author, it's your prerogative to choose the punctuation based on what you want your words to convey. For me, in this instance, using a period and creating two separate sentences felt a bit too detached. This comes from a female narrator whose fiance has very recently died. There is emotion and meaning in that small space between sentences, and using a semicolon to bring them together subtly highlights that relationship.
Have I helped you clear up any questions you had about semicolon usage? If not, feel free to ask a question in the comments.
J. Lea López is an author who strives to make you laugh at, fall in love with, cry over, and lust after the characters she writes. She welcomes online stalkers as long as they're witty and/or adulatory. Kidding. Maybe. Check for yourself: Twitter, Facebook, Blog. She will also take her red pen to your words if you ask nicely enough.