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Punctuation

It's essential to use proper punctuation marks to ensure your message is clear and understandable. This section will provide the correct usage and guidelines for the most common types of punctuation and help you avoid common mistakes.

Apostrophes​

The most common use of an apostrophe is to indicate possession of a word. For singular words ending in "s," add apostrophe and "s." For plural words ending in "s," just add an apostrophe. For example:

  • The code editor highlighted Adam's syntax error.
  • The code editor highlighted Sarah's syntax error.
  • The code editor highlighted the developers' syntax errors.

Colons​

When creating a list, it is best to use a colon instead of an ellipsis, em dash, or comma, to separate the previous sentence from the following items.

  • The web development software supports multiple programming languages: HTML, CSS, and JavaScript.

To connect two related phrases, you can use a colon. Remember to capitalize the first word if a complete sentence follows the colon.

  • I encountered a problem: The server was down, but the issue was resolved quickly.

Commas​

For your list writing, always include the serial comma, also called the Oxford comma.

❌   Not recommended
The website features responsive design, accessibility and search engine optimization.
👍   Recommended
The website features responsive design, accessibility, and search engine optimization.

If you are unsure when to use commas correctly, rely on your common sense. Try reading the sentence aloud and using a comma where you naturally pause or need to separate ideas.

Dashes and hyphens​

When linking words into a compound word or indicating a span or range, use a hyphen (-) without spaces on either side.

  • user-friendly interface
  • Monday-Friday

To set apart an aside, use an em dash (—) with no spaces on either side. Make sure to use a real dash, not hyphens (- or --).

  • The new feature—real-time collaboration—enhances team productivity.

  • Tom thought it was a bug, but he was wrong—it was a user error.

Question marks​

Be careful when using with quotation marks.

Question marks go inside quotation marks if they’re part of the quote. Like periods, they go outside parentheses when they are associated with a main sentence, and inside parentheses when the content related stands alone.

In this example, the question mark is part of the quote, so place it inside the quotation marks: "Are you familiar with the CSS framework Bootstrap?" The instructor asked.

When the content related to a question mark is alone, place the question mark inside the parentheses following the content, such as in the following example: The developer suggested using a JavaScript library (React?) for the project. Otherwise, when they are associated with a leading sentence, it would be: The developer suggested using a JavaScript library (React)?

Exclamation points​

For exclamation points, please follow the guidelines below:

  • Use exclamation points wisely, only using one at a time. Avoid doing it excessively.

  • Try don't use exclamation points in failure messages or alerts. When in doubt, avoid it.

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

Quotation marks​

Quotation marks are essential when referencing words and letters, titles of short works like articles and blog posts, and direct quotations.

Periods and commas go within quotation marks. Question marks within quotes follow logical rules: place them inside the quotes if they are part of the quoted material and outside if they apply to the whole sentence.

Use single quotation marks for quotes within quotes. For example:

  • Who said, "Less is more"?

  • Rachel said, "I read an interesting article titled 'The Power of Simplicity.'"