The semicolon (";") is a mark of punctuation most commonly used to separate independent clauses that share the same general idea or ideas, suggesting a closer connection between the clauses than a period does.

English author Beryl Bainbridge described the semicolon as "a different way of pausing, without using a full stop." Semicolons still appear fairly often in academic writing; however, they have fallen out of fashion in less formal kinds of prose — as Associated Press editor Rene Cappon advises, "you would do well to keep semicolons at a minimum."

That said, semicolons can also be used to separate items in a series containing commas to distinguish each item from the next group of items. Learning how to use the semicolon effectively can drastically improve the flow and clarity of a written work.

Rules and Usage

Although contentious in the modern literary world, semicolon usage has a long history of serving a vital purpose in written English, allowing for a flow and eloquence to prose, a rhythm set by variations in punctuation as well as word choice.

The most useful and indeed practical usage rule for semicolons might be its usage to separate items in a list that contains commas. This is especially useful when separating lists of people and their job titles — such as "I met John, the painter; Stacy, the business executive; Sally, the lawyer; and Carl, the Lumberjack at the weekend retreat" — to prevent confusion.

As Irish author Anne Enright put it in Jon Henley's "The End of the Line," the semicolon is also useful "when you need a sentence to shift or surprise; to be modified or amended; it allows a generosity, lyricism, and ambiguity to creep into the sentence structure." Basically, Enright posits that semicolons have their purpose, but should be used with care to avoid seeming self-indulgent or linking too many independent clauses together without giving the reader a break.

The Decline of Semicolons

This idea that semicolons are meant to provide a pause but still link independent clauses together in a piece of writing has all but died out in modern English usage, at least according to some English critics like Donald Barthelme, who describes the punctuation mark as "ugly, ugly as a tick on a dog's belly."

Sam Roberts says in "Seen on the Subway," that "In literature and journalism, to say nothing of advertising, the semicolon has been largely jettisoned as a pretentious anachronism. Especially by Americans," wherein "we prefer shorter sentences without, as stylebooks advise, that distinct division between statements that are closely related but require a separation more prolonged than a conjunction and more emphatic than a comma."

Critics across the board argue that semicolons, though highly useful in scholarly articles and academic papers, are best left to use there and have no usage in modern prose and poetry, where they come across as inauthentic and braggadocious.

How to Use Semicolons

Another possibility is that some writers simply don't know how to use the semicolon correctly and effectively. And so, for the benefit of those writers, let's examine its three main uses.

In each of these examples, a period could be used instead of the semicolon, though the effect of balance might be diminished.

Also, because in each case the two clauses are short and contain no other marks of punctuation, a comma might replace the semicolon. Strictly speaking, however, that would result in a comma splice, which would trouble some readers (and teachers and editors).

Use a semicolon between closely related main clauses not joined by a coordinating conjunction (and, but, for, nor, or, so, yet).

In most cases, we mark the end of a main clause (or sentence) with a period. However, a semicolon may be used instead of a period to separate two main clauses that are closely connected in meaning or that express a clear contrast.

Examples:

"I never vote for anyone; I always vote against."(W. C. Fields)

"Life is a foreign language; all men mispronounce it."(Christopher Morley)

"I believe in getting into hot water; it keeps you clean."(G. K. Chesterton)

"Management is doing things right; leadership is doing the right things."(Peter Drucker)

Use a semicolon between main clauses linked by a conjunctive adverb (such as however and therefore) or transitional expression (such as in fact or for example).

Examples:

"Words rarely express the true meaning; in fact, they tend to hide it."(Hermann Hesse)

"It is forbidden to kill; therefore, all murderers are punished unless they kill in large numbers and to the sound of trumpets."(Voltaire)

"The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd; indeed, in view of the silliness of the majority of mankind, a widespread belief is more likely to be foolish than sensible."(Bertrand Russell)

"Science in the modern world has many uses; its chief use, however, is to provide long words to cover the errors of the rich."(G.K. Chesterton)

As the last example demonstrates, conjunctive adverbs and transitional expressions are movable parts. Although they commonly appear in front of the subject, they may also show up later in the sentence. But regardless of where the transitional term makes its appearance, the semicolon (or, if you prefer, the period) belongs at the end of the first main clause.

Use a semicolon between items in a series when the items themselves contain commas or other marks of punctuation.

Ordinarily, items in a series are separated by commas, but replacing them with semicolons can minimize confusion if commas are needed in one or more of the items. This use of the semicolon is especially common in business and technical writing.

Examples:

The sites being considered for the new Volkswagen plant are Waterloo, Iowa; Savannah, Georgia; Freestone, Virginia; and Rockville, Oregon.

Our guest speakers will be Dr. Richard McGrath, professor of economics; Dr. Beth Howells, professor of English; and Dr. John Kraft, professor of psychology.

There were other factors, too: the deadly tedium of small-town life, where any change was a relief; the nature of current Protestant theology, rooted in Fundamentalism and hot with bigotry; and, not least, a native American moralistic blood lust that is half historical determinism, and half Freud."(Robert Coughlan)

The semicolons in these sentences help readers recognize the major groupings and make sense of the series. Note that in cases such as these, semicolons are used to separate all the items.