A client recently asked me about how to punctuate a sentence in her manuscript. Should the sentence read “My sister, Claire, planned the family reunion,” or “My sister Claire planned the family reunion”? Which was correct?

My answer was: “It depends.” To her credit, she didn’t throw her manuscript at me. How you punctuate the sentence above depends on which style guide you use and the meaning of the sentence.

Let’s start with the basics. The word “Claire” in the example above is an appositive. An appositive is a noun or pronoun that explains, renames, or identifies another noun or pronoun in the sentence. Here’s an example: The piano, a spinet, was hard to move. “Spinet” is an appositive that further defines “piano.”

An appositive can be a word, phrase, or clause. Here’s an example of an appositive phrase: The piano, a spinet that a friend was selling, was hard to move. While appositives can appear at the beginning, middle, or end of the sentence, they most often come after the nouns they explain, rename, or identify.

Examples:
Young women, their arms draped with leis, met the arriving tourists. (after the noun “women”)
Their arms draped with leis, young women met the arriving tourists. (beginning of the sentence)
Arriving at the airport, we saw the young women, their arms draped with leis. (end of the sentence)

Now comes the tougher part: how to properly punctuate an appositive. One rule, followed by many style guides and publications, says to use commas to separate appositives from the nouns they modify UNLESS the information in the appositive is necessary to understand the sentence. In this sentence, “the piano, a spinet, was hard to move,” the sentence would still make sense if you deleted the words “a spinet,” so the appositive is set off with commas.

However, if the appositive is necessary in order to understand the sentence, then you don’t need commas. In grammar guides, these words, phrases, or clauses that supply necessary information for sentence meaning may be called “restrictive appositives” or “restrictive clauses.”

Here’s an example: In high school, he developed an app that made him rich. If you remove “that made him rich,” the sentence doesn’t make as much sense. The appositive is necessary for the sentence’s meaning. One way to remember this rule is: Necessary information = no commas. Additional information = add commas.

Examples:
The City of Falls Church, which is known for its fine public school system, is only 2.2 square miles. (additional information, add commas)
Shakespeare’s play Twelfth Night is a comedy. (necessary information, no commas)

Let’s return to my client’s example: My sister Claire planned the family reunion. Does the sentence need commas? It depends. (Stay with me here.) Some style guides, such as the Chicago Manual of Style apply the rule above and say it depends upon whether the appositive is necessary information. If there is more than one sister, then the word “Claire” is necessary because it defines which sister planned the reunion. Necessary information means no commas. On the other hand, if there’s only one sister, then you can remove her name, and the sentence still makes sense. Additional information means adding commas.

However, some publications make an exception to this rule. They don’t bother with commas if the appositive is just a name, whether the information is necessary for meaning or not.

Examples:
My wife Joan is traveling for work this week.
She highly recommends her hairdresser Carlos.
His friend Paul will stop by today.

After considering all this, I told my client that her sentence about Claire didn’t need commas. That’s my position, and I’m sticking to it—no matter who throws what at me. 

The other day, I sent back an edited manuscript to a client, and she had a reasonable question. Why did the phrase “search and rescue” have hyphens in some places and not in others?

The answer came down to parts of speech.  What part of speech the phrase was in a particular sentence determined whether it took hyphens. If “search and rescue” is a noun—such as “I work in search and rescue” or “I do search and rescue,” then the phrase does not need a hyphen. However, if the phrase is a compound adjective that describes a noun, such as “a search-and-rescue dog” or “a search-and-rescue mission,” then the phrase takes hyphens.

So the same words in a manuscript sometimes need hyphens and sometimes do not. When a compound adjective appears before a noun, then hyphens help readers to see that the words make up a single unit to describe the noun. For instance, in this sentence—“I have a washer-and-dryer unit in my apartment”—it’s clear that the writer is referring to one appliance; without the hyphens, the meaning is unclear. In the sentence, “I have a washer and dryer unit in my apartment,” it’s possible that there are two appliances: a washer and a dryer unit (whatever that is). Also, if “washer and dryer” are nouns in the sentence, such as “the stacked unit combines a washer and dryer,” then no hyphens are needed since the meaning is clear.

Here are other examples of phrases that will take hyphens when used as compound adjectives but will not when they appear in the sentence as nouns:

When deciding whether to add hyphens, look at the phrase. What part of speech is it in the sentence? If the words are nouns, then they likely do not need a hyphen between them. If they are adjectives and make up a single unit that describes a noun, then add the hyphens.

This elegant symbol was originally a combination of the letters e and t in et, the Latin word for and. The first appearance we know about was in Pompeii, when an unknown graffitist in a hurry scrawled it on a wall circa 79 A.D.

Although the symbol goes back nearly two thousand years, its name is a relative newcomer. Scholars believe the name ampersand originated in the nineteenth century, when the symbol & was included as the last letter of the alphabet. When children recited the alphabet aloud, they prefaced A, I, and & with per se, which meant by itself, because  when spoken aloud, A, I, and & create separate words. The children’s recitation sounded like this: “Y, Z, and per se and.” Over time, those words slurred together as ampersand.

The ampersand has a few specialized uses:

Remember, the ampersand is a specialist. Even though it means and, the word and symbol are not interchangeable.

If asked how they generally use a colon, my guess is that most people would respond “as part of the :) emoticon.” Fortunately, it’s easy to learn how to use colons correctly. A colon has two functions: to introduce or to separate.

A colon introduces a list. For instance, “Lauren showed me her collection from the beach: shells, pebbles, and sea glass.” However, it's incorrect to use a colon if the list is a direct object or the object of a preposition. Here are two examples of lists that don't need colons: Lauren collected leaves, rocks, and feathers on her walk OR Lauren is interested in rocks, minerals, and fossils. Another mistake I often see when editing is using semicolons instead of colons to introduce a list.

A colon can also introduce a formal statement or quotation. For example, “The PTA released a statement yesterday: ‘The organization increased the scope of its teaching grants last year, and more teachers applied for grants for science and mathematics projects.’”

The second function of colons is to act as a separator. A colon separates two independent clauses when the second clause restates or explains the first. For example, “The store’s return policy is typical: it requires a receipt for cash back.” Often a semicolon can be used instead, particularly if the independent clauses are closely related.

Colons also act as separators between the following:

Keep in mind these few simple rules, and you’ll be ready to use the colon as more than just half of a smiley face.

What's the quickest way to bring out Mr. Hyde serial killers from a mild-mannered group of Dr. Jekyll editors? Ask whether the serial comma is necessary. Also called the Oxford comma, the serial comma, as the name implies, is used in a series. It precedes a conjunction and separates the last two items: "Gemma sent invitations to Pat, John, and Martha."

Few topics on punctuation provoke stronger opinions or more angst than the Oxford comma. Those who advocate for its demise square off passionately against fans equally determined to save it.

This comma received its name from Oxford University Press, where printers and editors used it in publications. Today, many style guides call for the Oxford comma, including The Chicago Manual of Style, Modern Language Association Style Manual, American Medical Association Manual of Style, U.S. Government Printing Office Style Manual, Publication Manual of the American Psychological Association, and the venerable Elements of Style. 

However, The Associated Press Stylebook, The New York Times, and The Economist omit the Oxford comma, claiming it's unnecessary and wastes space. Ironically, while Oxford University Press continues to use the comma, Oxford's public relations department does not. Neither does the rest of the United Kingdom, Canada, and Australia.

Whether I include the Oxford comma depends on my clients. If they follow The Associated Press Stylebook, then I omit it. If left to my own devices though, I always use it for two reasons. 

It clarifies meaning. While the extra comma is not strictly necessary for understanding simple lists such as "she wore a leotard, tights, and a tutu," the meaning may be ambiguous in more complex lists. For example, "I want to thank my teachers, Eliza and Lauren." Are the teachers Eliza and Lauren?  Or is the speaker thanking the teachers, Eliza, and Lauren?

Imagine a will in which the estate is divided among "James, Annie and Joy." Does James get one half of the estate, while Annie and Joy split the other half? Or does each receive a third of the estate?

The second reason to use the Oxford comma is it indicates a pause that mimics speech. When I write scripts with narration or dialogue, I include the final comma. It's hard to read "invitations to Pat, John and Martha" as punctuated; my voice wants to put in that extra comma. Omitting it affects meaning as well. Do John and Martha receive a joint invitation or separate ones?

The Oxford comma clarifies meaning and matches the rhythm of human speech. For those reasons, I'm a dedicated fan. You too can be a fan and give this punctuation mark some love. The Oxford comma has its own Facebook page.

When I was writing plays, I loved the ellipsis. Those three little dots were my go-to punctuation to end a line of dialogue. They indicated a pause before a profound thought. They hinted at deep meaning, those stepping stones to infinity. They also hid that I couldn't figure out how to finish the line. If ellipses were good enough for playwright Harold Pinter (who used them to punctuate the famous "Pinter Pauses"), then those three dots were good enough for me.

The ellipsis serves two purposes.
1. It indicates where words have been omitted from a longer text.
Example: We the People of the United States ... do ordain and establish this Constitution for the United States of America.

2. The ellipsis indicates a trailing off at the end of a sentence. It's often used this way in dialogue. In the middle of a line, the ellipsis indicates a hesitation, and then the thought continues.
Examples:
A long time ago in a galaxy far, far away ...
"You can't possibly mean ..."
"I thought ... when he said he'd written the check ... well, that the bill was paid."

The ellipsis places high on Internet lists of grammatical peeves. Many of us don't know how to correctly space ellipses or what to do with them at the end of a sentence. Style guides aren't much help, because they differ in their advice. I favor this guidance because it's sensible and easy to remember: space the dots by replacing the ellipsis with a three-letter word, like "car." There should be a space before and after the word, with no spaces in between. Treat ellipses the same way.
Examples:
She bought a new car yesterday.
It was frightening ... I couldn't imagine what could be growling at the back of the closet.

If the ellipsis falls at the end of a complete sentence, then end that sentence with a period, insert a space, then insert the ellipsis to indicate where words have been omitted.
Example: We have warned them from time to time of attempts by their legislature to extend an unwarrantable jurisdiction over us. ... We must, therefore, acquiesce in the necessity, which denounces our Separation, and hold them, as we hold the rest of mankind, Enemies in War, in Peace Friends.

To make an ellipsis, type three periods without spaces between them. In Microsoft Word, you can insert an ellipsis by using the "insert symbol" menu.

An ellipsis may not indicate a path to infinity, but it's still a pretty useful punctuation mark.