Dashes

Dashes are often used to mark interruptions within sentences. They can also be used to show value ranges and relationships between words. There are two kinds of dashes: em dashes ("—") and shorter en dashes ("–"). En dashes generally have a space before and after the dash. In some situations, either an em dash or an en dash is appropriate. One can either use em dashes without spacing or en dashes with spacing, but not em dashes with spacing. For example:

• Three unlikely companions—a canary, an eagle, and a parrot—flew by my window in an odd flock. (em dashes)
• Three unlikely companions – a canary, an eagle, and a parrot – flew by my window in an odd flock. (en dashes)

The Em Dash

Em dashes are also used to indicate that a sentence is unfinished because the speaker has been interrupted. Similarly, they can be used in place of an ellipsis to illustrate an instance where a sentence is stopped short because the speaker is interrupted or too emotional to continue. For example:

• "Hey," said Paul, "where do you think—"
• "I never understood why you—" Cesar trailed off.

Em dashes are also sometimes used to summarize or define prior information in a sentence. For example:

• When he saw his brother—his long-lost brother who disappeared six years prior—he broke down in tears.
• Today is St. Patrick's Day—a day for family.

The En Dash

En dashes should be used to demonstrate definite ranges of values. In these cases, there should not be any spaces around the en dash. For example:

• June–July 1967
• 1:00–2:00 p.m.
• For ages 3–5
• pp. 38–55
• President Jimmy Carter (1977–1981)

The en dash can also be used to contrast values, or illustrate a relationship between two things. For example:

• Radical–Unionist coalition
• New York–London flight
• Mother–daughter relationship
• The Supreme Court voted 5–4 to uphold the decision
• The McCain–Feingold bill

An exception to the use of en dashes is made, however, when combined with an already hyphenated compound. In these cases, using an en dash is distracting. Use a hyphen instead. For example:

• Non-English-speaking air traffic controllers
• Semi-labor-intensive industries

When he saw his brother—his long-lost brother who disappeared six years prior—he broke down in tears.

The title contains an example of em dash usage, which, in this case, shows a break in the sentence.