Grammar and mechanics: Punctuation.

This section clearly lays out the editorial rules and standards we abide by. The result is that our content is consistent and free of error.


The most common use of the apostrophe is making a word possessive. If the word already ends in an s and it’s singular, add an’s. If the word ends in an s and is plural, add an apostrophe.

  • The car thief stole John’s car.
  • The car thief stole Chris’s car.
  • The car thief stole the girls’ cars.


Use a colon (not an ellipsis, em dash, or comma) to offset a list.

  • Marvin ordered three kinds of pies: apple, pecan, and blueberry.

Use a colon to join two related phrases. If a complete sentence follows the colon, capitalize the 1st word.

  • I was faced with a dilemma: I wanted a donut, but I’d just eaten a bagel.


When writing a list, use the serial comma (commonly known as the Oxford comma).

  • Yes: Tim respects his friends, parents, and teachers.
  • No: Tim admires his friends, parents, and teachers.

If you’re unsure, use common sense to figure out what to do. Read the sentence aloud, and then insert a comma wherever you find yourself taking a breath.

Dashes and hyphens.

Use a hyphen (-) without spaces on either side to link words into a single phrase or indicate a span or range.

  • first-time user
  • Monday-Friday

Use an em dash (—) with spaces on each side.

Use a true em dash, not hyphens (- or --).

  • A/B testing — something we strongly believe in — can help lead to your company’s success.
  • John thought Tina was the good one, but he was wrong — it was Jane.


Ellipses (...) show that you’re trailing off before ending a thought. Use them on rare occasions. Avoid using them for emphasis, and never use them in titles or headers.

  • “Who put my shoes in there?” Sergio asked. Darryl said, “I don’t know...”


Periods should be placed inside quotation marks. They go outside parentheses when the parenthetical is part of a larger sentence. They go inside parentheses when the parenthetical stands alone.

  • Steven said, “I drank some juice.”
  • He ate a cookie (and he ate a donut, too).
  • She ate a sandwich and an omelet. (The sandwich was Tim’s.)

Leave a single space between sentences.

Question marks.

Question marks belong inside quotation marks if they’re part of the quote. As with periods, they go outside parentheses when the parenthetical is part of a larger sentence.  When the parenthetical stands alone, however, they go inside parentheses.

Exclamation points.

Be stingy with exclamation points, and never use more than one at a time.

Exclamation points go inside quotation marks. As with periods and question marks, exclamation points go outside parentheses when the parenthetical is part of a larger sentence and inside parentheses when the parenthetical stands alone.

Never use an exclamation point to deliver a failure message or alert. When in doubt avoid!

Quotation marks.

Use quotes when referring to words and letters, titles of short works (such as articles and poems), and direct quotations.

Place commas and periods in quotation marks. Use logic when figuring out how to write question marks within quotes. For example, if the question mark is part of the quotation, it goes inside the quote. If you’re asking a question that ends with a quote, it goes outside the quote.

Use single quotation marks for quotes within quotes.

  • Who was it that said, “A fool and his donut are easily parted”?
  • Brad said, “A wise man once told me, ‘A fool and his donut are easily parted.’”


Tread lightly with semicolons. They’re typically used for unnecessarily complicated sentences that could easily be simplified. Go with an em dash (—) instead, or create a new sentence.


Never use the following symbols in copy, subheadings, or titles. Instead, write out their actual meaning.

  • & – and
  • # – hashtag
  • < – less than
  • > – greater than

There is one exception to this rule – if the symbol is part of a brand identity, then use the symbol.