When you mean to suggest a close relationship between two separate statements, consider joining them with this highly effective punctuation mark.

As we have discussed in this column, a comma may be used to combine two sentences into one. But danger lurks in doing so. If you neglect to include a coordinating conjunction such as but or and immediately after the comma placed after the first independent clause, which is a group of words containing a subject and a verb that can stand alone as a sentence, you will have created a “comma splice,” or run-on sentence. And that is an abomination which the clerk or judge reading your brief will view as a signal to scrutinize your discourse for other evidence of sloppiness. Consider avoiding the risk by opting instead for the simple elegance of a semicolon, like so:

The defendant moved to strike parts of the complaint filed against him; he said those portions were redundant and immaterial.

The first letter of the first word of the clause following the semicolon should be lower case unless the word is a proper noun.

Sadly enough, the semicolon has become one of the least used types of punctuation in sentence construction, despite their ability “to add variety to your writing and help keep it from seeming choppy,” as Richard Wydick touts the mark in Plain English for Lawyers (5th ed.). In The Elements of Legal Style (2nd ed.), Bryan Garner attributes the scarcity of semicolons to uncertainty about their proper use.

With that in mind, let us illuminate the question.

Use a semicolon to join two independent clauses when they are closely related.

Where you have two independent clauses, and the second clause, for example, expands on or provides further detail concerning the first, a semicolon is an appropriate mark to place after the first to indicate a mere pause between the two, rather than the hard stop that a period would signal.

Here’s an example that Garner plucked from Robert G. McCloskey’s The Modern Supreme Court, published in 1972, for use in The Elements:

The war had been not merely a profoundly unsettling experience in itself; it had also marked for America the beginning of unaccustomed and vexing entanglements in international affairs.

Here’s one from Plain English: Plaintiff Munoz had just witnessed his wife’s death; he was in a state of deep shock.

And here’s what William Strunk and E.B. White have to say on the matter in the third edition of The Elements of Style:

If two or more clauses grammatically complete and not joined by a conjunction are to form a single, compound sentence, the proper mark of punctuation is a semicolon.

Strunk and White give us these two examples:

• Stevenson’s romances are entertaining; they are full of exciting adventures.
• It is nearly half past five; we cannot reach town before dark.

In each example above, you could of course turn the two independent clauses into separate sentences. But, as Strunk and White point out, you would have missed the opportunity to suggest the close relationship between the two. Strunk and White are huge fans of the semicolon’s appearance in this context, calling it “one of the most useful devices in composition.” They characterize the close relationship between two independent clauses that would best be joined by a semicolon as “commonly one of cause and effect.”

When the first independent clause ends in a quotation mark, be sure to place the semicolon after it: He told us to strive to “make a positive difference in people’s lives”; one day they may return the favor.

Wydick also instructs writers to use a semicolon when the second independent clause begins with a transitional expression such as therefore, however, furthermore, thus, indeed, in fact, as a result, or for example. Here are his examples:

• The court granted the preliminary injunction; therefore, the company could not fire the plaintiff while the case was pending.
• The witness had no personal knowledge of the event; in truth her testimony was hearsay.
• Her testimony could have been admitted under several exceptions to the hearsay rule; for example, either the excited utterance exception or the contemporaneous statements exception would apply.

The two other proper uses of the semicolon involve lists and appear regularly in legal writing.

Use a semicolon to separate items in a list of things that themselves contain commas.

We do that to avoid ambiguity and confusion.

Here is Garner’s example: The company has offices in Bartlesville, Oklahoma; Theills, New York; and Greenville, North Carolina.

Here is Wydick’s: The prosecutor called the following witnesses: Susan Wu, a psychiatrist; Michael Bradford, a ballistics expert; and George Frye, a police investigator.

Use a semicolon to separate items listed after a colon.

(I did not do so after the bulleted items above to highlight where the conjoining semicolons should be placed.)

Here is an example from Garner’s The Elements of Legal Style:

The board of regents gave three reasons for rejecting the committee’s report: (1) the report insufficiently addressed the factual allegations that the president had violated faculty members’ academic freedom; (2) it did not name any sources for the information on which it relied; and (3) it drew conclusions that the board of regents was unprepared to accept.

In keeping with the rule governing use of semicolons when joining independent clauses, the first letter of the first word of the itemized statement following the semicolon should be lower case, unless the word is a proper noun.

Here is one final example from Garner, which he took from Oregon v. Mitchell (1970) 400 U.S. 112, 136-37 (Douglas J., dissenting in part and concurring in part) (footnotes omitted):

The case was followed by numerous others, e.g.: that one person could not be given twice or 10 times the voting power of another person in a statewide election merely because he lived in a rural area or in the smallest rural county; that the principle of equality applied to both Houses of a bicameral legislature; that political parties receive protection under the Equal Protection Clause just as voters do.

Let us go forth now with the courage to diversify our writing by using a semicolon where appropriate.