We use many punctuation marks intuitively. We put periods at the end of sentences without any problem. Exclamation points clearly convey strong emotions. Question marks mark questions. Most of us feel confident with commas as well, although we might harbor a vague fear of unintentionally committing a “comma splice.” But what are we supposed to do with semicolons?
For me, the least mysterious way to use semicolons is to separate items that themselves contain punctuation in a series. A student writing a history paper might have a thesis statement like this: “The causes of the American Revolution were the colonists’ unhappiness with the Stamp Act, as well as with taxes on goods such as china, glass, lead, paint, paper, and tea; the British government’s passing of the Intolerable Acts, which, among other things, rescinded the charter of Massachusetts, forced colonists to house British soldiers, and made royal officials immune to criminal prosecution; and the Boston Massacre – the spark that lit the powder keg – when British soldiers fired at a crowd of Americans.” (Good luck to the teacher who has to read that three-page paper!) This sentence is already hard to parse; without the “serial semicolons” identifying which parts go together, it would be almost impossible to understand.
Semicolons are also used “to link (in a single sentence) two independent clauses that are closely related in thought,” according to the University of Wisconsin Writer’s Handbook. This is where the anxiety creeps in. What’s an independent clause? How can you tell if two clauses are related closely enough?
For a long time, I only felt confident putting semicolons in sentences like this: “I love vanilla ice cream; my husband prefers chocolate.” It’s clear that these two clauses are independent – that they could each make sense as a stand-alone sentence. And it’s obvious that they are related, since they have a parallel structure and are both about ice cream. A comma wouldn’t work here because commas accompany dependent clauses. Connecting two stand-alone clauses this way – “I love vanilla, my husband prefers chocolate” – makes for the dreaded comma splice.
There is a sort of formula that will allow anyone to go forth and place semicolons boldly. A semicolon = a comma + a coordinating conjunction. Whenever you have two independent clauses connected by “, and” or “, but” you can use a semicolon.
Semicolons and conjunctions are readily interchangeable in the sentence above: “I love vanilla ice cream, and my husband prefers chocolate.”
We don’t labor over when to choose and or but; similarly, we don’t need to struggle with the semicolon.