Hyphens & Dashes

Double hyphens

Don’t use them. Instead, use the em dash (—).


Em Dashes

These are long dashes, the equivalent length of an M (—), used to set off parenthetical text or digressive elements. There should be no space on either side:

This has been a long haul—to Hades and back—for everyone involved.


En Dashes

Half the length of the em dash (–). Used between inclusive numbers, to show a range.

The cost is $50–$55.
My weight has ranged from 125–165 lbs in the last decade.

Sports scores do not indicate a range, and therefore use a hyphen.

To make an em-dash or an en-dash in Word on a PC or Mac:

  • place your cursor where the mark will go
  • go to “Insert” in the program menu and open up “Symbol”
  • highlight the appropriate symbol
  • click “insert”

Mac key codes:

  • em-dash: option/shift/hyphen
  • en-dash: option/hyphen

PC key codes:

  • em-dash:  shift + alt + hyphen
  • en-dash:  “windows symbol key” + alt + hyphen

Or, create your own shortcuts by following the directions in the Symbol section


With Prefixes & Suffixes
In general, prefixes are not followed by hyphens unless the resulting word can be confused with another word, is difficult to decipher, or precedes a number or a capitalized word.

co: coauthor; cowriter; codirector; coedit; but co-chair
no hyphen unless word ends in l. lifelike; funnel-like
midwinter; midyear; midlife; mid-Atlantic; mid-August; mid-1990s
nonprofit; nonstudent; nonmajor
preprofessional; premed; prelaw

Suspending hyphens:
Use when a series of hyphenated adjectives modifies the last noun in the series:

first- and second-level courses
two- and three-year-old children

With Measurements:
Hyphenate measurements that serve as adjectives preceding a noun:

The bandage is a two-inch-long strip of gauze.
Place this four-foot block of wood in the fire.

Connect measurements with hyphens when the numbers represent a range, and they function as an adjective preceding a noun:

We knew that the tsunami might create 80-to-90-foot tidal waves.

With Fractions:
Hyphenate spelled-out fractions when used as modifiers, unless the numerator or denominator is already hyphenated. Whole numbers are not linked to the fraction with hyphens.

one-half empty; two-thirds majority
fifty-six hundredths; four twenty-fifths
five and three-tenths inches

With Whole Numbers:
Hyphenate from 21 to 99 when spelled out:

twenty-one; ninety-nine; one hundred forty-eight

With Sports Scores
Sports scores do not indicate a range, and therefore use a hyphen.

The game ended in a 21-21 tie.
Middlebury won in double overtime, 3-2.