The first step in understanding grammar is realizing punctuation does not make English work all by itself. Clarity comes from the structure of the sentence; punctuation just acts as the signage to make the roadway safer. To know where to put all those yield signs and stop lights, one must first understand how to break down a sentence.

Sentence Structure

We’ve all heard the words noun, verb, adjective, and object. But you may not have spared a thought for your sentence structure in over a decade!

Sentence structure centers on the action, just like a novel centers on the climax. If you can locate the verb (the action) of the sentence, you’re doing pretty well:

The highly sophisticated man hesitated to buy more champagne.

Wait, “hesitated” is a verb, but isn’t “to buy” also a verb? True, but since “to buy” is does not agree with the subject, we know it’s not the main action verb of the sentence. “Buying” is not what happened; what happened was the man “hesitating.”

In this example, “to buy” is a noun (the object of the sentence) and “to buy more champagne” is the full noun phrase. “Man” is also a noun in the full noun phrase, “the highly sophisticated man.”

A full noun phrase includes smaller units (articles, like “the,” and adjectives, like “highly sophisticated”). “Highly sophisticated” is a compound adjective composed of an adverb and an adjective. Many different combinations exist for compound adjectives; to better understand them we need to talk a bit about hyphens.

Hyphens

Hyphens are great for connecting words to achieve more precise meanings:

the “miniature dog competition” or

the “miniature-dog competition”

In the first example, we have a miniature competition for dogs; in the second, we have a competition for miniature dogs. The hyphen tells us that “miniature” modifies “dog,” making a compound adjective that modifies “competition.”

Compound adjectives come in different combinations that require hyphens, and here are just a few examples:

• Adverb & Adjective (requires a hyphen, unless ending in –ly): well-known businesswoman or highly sophisticated man
• Noun & Adjective (requires a hyphen): waste-free container or wild-goose chase
• Noun & Noun (requires a hyphen): Blue-green eyes or Salt-and-pepper hair
• Noun & Verb (requires a hyphen): Mind-blowing hypothesis

En-Dashes vs. Em-Dashes

En-dashes (–) work as super-duper hyphens: they can create compound adjectives by connecting other compounds, dates, times, etc.:

• White House–like mansion
• United Kingdom–United States relations
• 1856–1943
• 7:30–8:45

However, unlike hyphens and en-dashes, em-dashes (—) work to connect parts of a sentence instead of words.  Em-dashes are one of three punctuation options for parentheticals: commas, em-dashes, and parentheses. (More on parentheticals below.)

Visually these dashes can be deceiving but they are actually each different lengths. The hyphen is a short dash, while the en-dash is the length of a capital N and the em-dash is the length of a capital M. Since typewriters wrote in a monospaced typeface (like the font “Courier”), en-dashes and em-dashes were mimicked by using two hyphens in a row. Because of this tradition of typing, word processors on computers (like Microsoft Word) will translate two hyphens and automatically replace them with the en-dash and em-dash characters.

• Between two words, type a space, two hyphens, and a space to create an en-dash
• Between two words, type two hyphens without spaces to create an em-dash

Your word processor will replace the punctuation as you continue typing your sentence.

Parentheticals (Parentheses vs. Commas vs. Em-Dashes)

Parentheticals in sentences are like asides in a play: they’re inserted when you have extra information that the audience needs, even though the information doesn’t explicitly affect the action.

In the examples below, the sentence still centers on the action: what is being done (“hesitating to buy champagne”) and who is doing it (“the highly sophisticated man”).  All other information is extraneous, and it should be set apart in parentheticals.

The three types of parenthetical punctuation determine whether your actors will whisper, speak, or shout the aside.

Parentheses: “whispering,” or suppressing the information.

The highly sophisticated man hesitated to buy more champagne (even though it was on sale).

Commas: “speaking,” or providing no emphasis on the information.

The highly sophisticated man, because it was an unfamiliar brand, hesitated to buy more champagne.

Em-dashes: “shouting,” or drawing attention to the information.

The highly sophisticated man—who recently lost his fortune—hesitated to buy more champagne.

But what happens if we relocate the parenthetical in the second example?

The highly sophisticated man hesitated to buy more champagne, because it was an unfamiliar brand.

Because it was an unfamiliar brand, the highly sophisticated man hesitated to buy more champagne.

Oh, no!  “Because” at the beginning of a sentence!? Don’t worry: it’s okay! The entire parenthetical is acting as an introductory phrase, which is totally legit. (I promise that your elementary school teacher isn’t going to come after you in your sleep tonight.) Notice that there is only one comma in each of these sentences. This is because commas and en-dashes do not need to come in pairs the way parentheses do: think of them like bookends, which can hold up a stack of books against a wall to the left or right.

Terminal Punctuation in Parentheticals

One final punctuation tip: terminal punctuation (periods, exclamation points, and question marks) sometimes go within parentheses and sometimes don’t. So how do you know where to put them?

A terminal punctuation mark will go on the outside when it applies to a larger sentence, but when an entire sentence is enclosed in parentheses, the punctuation will stay with its sentence.

An easy way to figure it out is to locate your verb: if the verb is inside, so is the period; if the verb is outside, the period is too.