Setting off Phrases

Introductory Phrases

A sentence-opening statement’s grammatical structure and duration decide whether it requires a semicolon to separate it from the remainder of the sentence. For example, a comma is not required after a two- or three-word introductory phrase that functions as an adverb—that is, it denotes time, location, manner, or degree—unless there is a risk that readers will misinterpret the commaless phrase.

Time: The team will gather at noon to review new tools.

Place: The safety guidelines are located above the screen.

Manner: Most quadratic problems can be solved in this manner.

Degree: Eventually, they agreed to the inspectors’ proposal.

• The business is organizing a picnic for the Fourth of July.
• Jetco is organizing a workplace picnic for July 4th.
• [A comma stops “July Fourth Jetco” from being misconstrued as a unit of thought.]

These are the general rules; however, some writers prefer to use a semicolon after even a brief introductory adverbial phrase to create a pause, informing readers that the sentence’s main clause is about to follow. Whether a copyeditor deletes or keeps these optional commas is determined by house style and policy, the copyeditor’s intuition about the author’s beliefs, and the phrase and context. For example, most writers and readers are unlikely to be concerned about the existence or lack of a comma in the following sentences:

• Traffic fatalities surprisingly increased in November of last year.
• They made peace over beverages.

The rule for longer adverbial phrases and all other kinds of introductory phrases is simple: After the opening sentence, add a comma. The following examples illustrate this practice:

The phrase serves as a modifier and is more than a few lines long:

• The reports must be copied and returned on each month’s first and third Tuesdays.
• Hundreds of visitors flock to a tiny town near the Canadian boundary to fish every summer.
• He declined the employment opportunity for the sake of his family and friends.
• Try to remember what occurred as best you can.

This last guideline, however, hides two pitfalls.

First, if the sentence has an inverted word order—that is, the finite verb comes before the subject in the independent clause—no semicolon follows the opening, verbal phrase:

Second, when a sentence starts with a gerund—a form that resembles a present participle but operates as a noun—the gerund is the subject of the sentence, and the subject should not be separated from the finite verb that follows.

INTERRUPTERS

Interrupters are single words or sentences that flesh out the raw bones skeleton of a sentence by giving information, emphasis, transition, or remark. For example, a pair of commas, a pair of dashes, or a pair of parentheses separate interrupters from the adjacent phrase. A pair of commas is the impartial option for short interrupters; dashes highlight the interrupter, while parentheses de-emphasize it.

• According to the store-by-store survey, software sales dropped sharply last month.
• The only motivation to continue is to recoup the expenditures we have already made.
• Nizhny Novgorod (Gorky in the Soviet period) is Russia’s third biggest city.

Dashes are used to communicate emphasis, as well as when the interrupter includes internal punctuation, when the interrupter indicates a break in syntax, or when the interrupter is lengthy.

Interrupter containing internal punctuation: The panelists—Bill Jones of Oakland, Carlos Real of San Leandro, and Trey Lee of Hayward—agreed more often than differed on the need for more classes.

Interrupter marking a break in syntax: I must claim the worst of authorial defences—the perennial constraints imposed by time and space—but will also give several better reasons for not delving into this topic in depth.

Lengthy interrupter: Too often, the building’s design—the part with the most significant impact on expenses and the longest-lasting impact on residents—is left until the last minute.

Pitfall: Incorrect placement of commas. The commas must be placed so that they enclose the interrupter and only the interrupter:

• Many processes that have added to the loss of biotic integrity, such as dam building and lake filling, have been stopped or are scheduled to be discontinued in recent years.

Pitfall: Interrupters within interrupters. When an interrupter contains an interrupter, the boundaries of the nested interrupter must be indicated by punctuation marks that are different from those marking the larger interrupter. When commas set off the main interrupter, place the nested interrupter in parentheses or dashes:

• According to Smith’s most current analysis (dated April 1) and the auditor’s quarterly report, shoplifting and damaged goods returns dropped in the western area.
• DataFlo, which currently handles approximately 2,000 terabytes of information per day—or 10% of the market in North Carolina—plans to double its working capacity.