- In the sentence This is a sure-fire tip, the two words sure and fire form
an adjective compound modifying tip. When two or more words are
compounded
to form an adjective that precedes a noun, they are usually hyphenated
space-time continuum
state-of-the-art technology
long-range, high-power radar
- No hyphen is needed following adverbs that end in -ly
technically accurate manual
artificially induced sleep
- Adjectives ending in -ly are hyphenated when they are used with present participles
friendly-sounding voice
- Many compound words that are hyphenated before a noun are not hyphenated after the noun:
this is my up-to-date report Bring them up to date.
It is a well-known principle. The principle was well known.
- Do not hyphenate scientific terms, chemicals, diseases, and plant and animal names used as modifiers if no hyphen appears in their original form.
sulfur dioxide emissions
swine flu epidemic