The English language has several easily-confused horizontal-line punctuation symbols:
- Hyphen: –
- En Dash: –
- Em Dash: —
- Minus Sign: −
- Underscore: _
Although these punctuation marks look similar at a glance, they are actually distinct punctuation marks with specific intended uses and with distinct unicode character values. Let’s look at these different punctuation symbols and some of their common uses.
The hyphen (-) has several uses: compound adjectives (e.g., three-ring circus), prefixes (e.g., anti-intellectual), and (less commonly now) to split a word for a line break.
The hyphen appears on most contemporary English keyboards, but for the sake of completion its unicode value is U+2010.
En Dash (–)
The en dash (–) is chiefly used to represent a range. For example: 8–10 pages, 40–50 weeks, July–November, and so on. Note that no space appears before or after the en dash when used in this way.
Lesson commonly, the en dash is used to contrast words, names, or values, in ways that are distinct from compound adjectives. For example: Einstein–Rosen Bridge.
The unicode value for the en dash is U+2013. The en dash does not appear on most contemporary English keyboards, but it can be typed using the following keyboard shortcuts:
- Windows: ALT + 0150 (Hold down the ALT key and type 0150 on the numeric keypad.)
- Mac: OPT + - (Hold down the OPT key and press the - key.)
Em Dash (—)
The em dash (—) is most commonly used within a sentence in place of parentheses or a colon. For example:
- Three people—a butcher, a baker, and a candlestick maker—perished in the crash.
- I had Swedish pancakes for breakfast—it’s my favorite breakfast dish.
Another common use of the em dash is for interruptions. For example: “What the—?”
The unicode value for the em dash is U+2014. Like the en dash, the em dash likewise does not appear on most contemporary English keyboards. But it can be typed with the following keyboard shortcuts:
- Windows: ALT + 0151 (Hold down ALT and type 0151 on the numeric keypad.)
- Mac: OPT + SHIFT + - (Hold down the OPT and SHIFT keys and press the - key.)
Minus Sign (−)
The minus sign (−) is used chiefly in mathematical expressions to denote subtraction (such as 7 − 4 = 3) or to denote negative numbers or the negation of variables (such as −3 or −x).
The unicode value for the minus sign is U+2212. Although there is a subtraction key in the numeric keypad section of many contemporary English keyboards, unfortunately this key usually just yields a hyphen and not a true minus sign. Although there is a Windows keyboard shortcut for added the minus sign (ALT + 2212), this keyboard shortcut does not work on all Windows computers or in all programs. To add a true minus sign, I recommend one of the following two methods:
- Copy a minus sign from here (−) or from this Wikipedia page and paste where needed: Plus and Minus Signs on Wikipedia.
- From your word processor program, use the “Insert Symbol” feature—which varies from word processor to word processor—to insert a minus sign. Usually you can just search for “minus” to quickly locate the minus sign in the list of available symbols.
The underscore (_) originated on mechanical typewriters and was used as a means of underlining portions of previously typed text. The underlining text formatting feature of modern word processor programs has rendered this use of the underscore obsolete. The underscore has other contemporary uses in computer programming, which are beyond the scope of this article.
In educational content development, a series of underscores is occasionally used to represent a blank in quiz or exam questions. For example: “The distance from Earth to the Sun is approximately _______ million miles.”
Because of the low vertical placement of the underscore character on a line of text, the underscore is less likely to be confused with another punctuation mark than those described above.