Adjectives, Adverbs, and Nouns
Hyphenate
Adjective + noun [or participle] + noun, e.g., low-quality sound and tight-lipped person
Age terms, both adjectives and nouns, e.g., five-year-old and three-year-old child
Gerund + Noun + Noun, e.g., running-shoe department
Noun + gerund + noun, e.g., decision-making process
Noun + noun + noun, single function (adjective form), e.g., tenure-track position
Noun + noun, two functions (compounds as both adjectives and nouns), e.g., nurse-practitioner and city-state
Noun + participle (adjective form), e.g., flower-filled garden
Number [21-99] (spelled out), e.g., ninety-nine
Number + unit (not abbreviated) + noun, e.g., a 250-page book and a hundred-meter race
Number (ordinal) + noun + noun, e.g., third-floor apartment and first-row seats
Number (ordinal) + superlative + noun, e.g., second-best decision and third-largest town
Participle + noun + noun, e.g., chopped-liver pâté and cutting-edge methods
Participle + preposition + noun, e.g., a frequently referred-to paragraph
Simple fractions, e.g., one-half and three-quarters