–(In case of doubt, check a dictionary. Some common phrases are not hyphenated.)
Do not hyphenate if the descriptive words follow the noun.
- state-of-the-art technology
- technology that is state of the art
- science-based medicine
- medicine that is science based
- long-term solution
- a solution that will work long term
- water-based paint
- paint that is water based
- a five-year-old computer
- a computer that is five years old
Capitalizing hyphenated words
- The Hunchback of Notre-Dame
- The Vice-President Sleeps
- Is There a Sheep-Proof Fence?
- Seventy-Seven Serpents
- Academy Award winner
- Pizza Hut order
- Weather Channel forecast
- a very happy dog
- a finely tuned automobile
- a happily engaged couple
- The small-town mayor was re-elected every year.
- (The town was small. The mayor may or may not have been.)
- The small town mayor used a cushion in his chair.
- (The mayor of the town was small.)
Hyphenated adjectives with the same root in a list
- The snakes were three-, four-, and five-feet long.
- His eight-, ten-, and eleven-year-old boys are exactly the same height.
- Half- and three-quarter-ton pickups are often bought by city dwellers.
(If uncertain, check a dictionary.)
Ranges of time, distance, or estimates
- 8:00 a.m.-1:00 p.m.
- 100-115 dogs
- 3-5 miles
- thirty-five books
- sixty-two years
- seventy-six trombones
- ninety-nine bottles
- forty hours
Avoid confusion by hyphenating ages and spans of time .
- 25-year-old books
- (the books are all 25 years old)
- 25 year-old books
- (tells how many books are a year old)
- one-half of the cracker
- a half of the cracker, a half a cracker
- one-eighth of an inch
- an eighth of an inch
- three-fourths of a mile
- seven-tenths of a kilometer