fonts/cc-by-sa/knowledge/glossary/terms/hyphenation/content.md

Hyphenation is the act of using the hyphen character to either break single words over two lines, or connect multiple words. The former is the job of the typographer (usually aided by automatic tools built into design software or browsers); the latter is the job of the writer or editor.

“Cutting-edge” is connected with a hyphen; “typographer” is split over two lines with a hyphen.

When it comes to breaking words across lines, hyphenation is an essential part of any justified text, since it can be difficult to balance lines of text that are aligned to both and left and right margins without breaking longer words with hyphenation.

Using a hyphen to connect separate words can be contentious, so it’s always best to refer to the style guide we’re using. Generally, they can be used to create compound modifiers:

Is this a dog-friendly park?

Or compound words:

Sister-in-law

There is no situation in which using a double hyphen is acceptable. If tempted, use an en dash or em dash instead, and be sure to refer to the style guide.

Writing for the web and need guidance? Check out the Material IO Guidelines.