The hyphen is used for joining words in various types of compound constructions. There are numerous examples including compound nouns, adjectives, and verbs. I will not delve into the specific rules of using hyphens in these situations. More importantly, once you have read the rules regarding en-dashes and em-dashes, you will at least know when not to use hyphens.
Similarly, hyphens are used to join some prefixes and suffixes to nouns, adjectives, or verbs.
Hyphens are also used for joining parts of a word that have been separated by a line break.
You can also use hyphens to indicate the spelling of a word. For example, "Any decent Scrabble player knows the letter h is spelled a-i-t-c-h."
When you want to emphasize clear enunciation, use the hyphen as well: "I said, 'be qui-et!'"
The hyphen key appears on the top row on your keyboard, to the right of the zero. It also appears in the upper right hand corner of the number pad.
Notice than the en-dash is slightly bigger than the hyphen. The en-dash is so named because it is supposedly the length of a letter n.
En-dashes are used to separate compound expressions. Many compound expressions are geographical areas. For example, the San Francisco–Bay Area.
You also use en-dashes to indicate a range of numbers. For example, when writing the years a person lived: Jim Morrison (1943–1971). Or, for a range of pages: "Read pages 5–12."
The easiest way to insert an en-dash is using the shortcut:
—Hold down the Alt key on your keyboard
—Type the numbers 0–1–5–0 on your keyboard's number pad (Num Lock key must be activated)
—Release the Alt key
The en-dash appears.
In Microsoft Word, you can also add an en-dash in this way: add a space after the word you want the en-dash to follow, press the hyphen key twice, and then continue typing. Microsoft Word will then convert the two hyphens to an en-dash. However, it is good practice to go back and delete the initial space that you added. Most style guides suggest that you put no space before or after an en-dash.
The em-dash is the longest of the three. The em-dash is so named because it is supposedly the length of the letter m.
Em-dashes are used mainly to set off explanations within sentences. Many writers will often use round brackets (parentheses) in these situations. Often, the two are interchangeable though some will argue that there are differences and nuances.
For example: He met with other cruciverbalists—lovers of crossword puzzles—every Sunday night.
Em-dashes can also be used in place of colons in titles. And they can be used in place of bullets in vertical lists.
To add an em-dash, press Alt + 0151 on your keyboard.
Or, in Microsoft Word, immediately after the word that you want the em-dash to follow, press the hyphen key twice, and then continue typing. Microsoft Word converts two hyphens to an em-dash. As with en-dashes, most style guides suggest that you put no space before or after an em-dash.
And those are the basics for using hyphens, en-dashes, and em-dashes. Knowing how to use these correctly will set you apart from many writers.