Hyphens are an important part of writing sentences, and they are often overlooked. Hyphens should be used to join things and should not be confused with dashes, which serve a different purpose. Learn to use hyphens correctly in sentences.
Link compound modifiers with hyphens. A compound modifier is when two or more words together modify a single noun; link all of the words involved with a hyphen, whether they appear before or after the noun. Example: "A first-rate student" or "the 10-year-old boy." This does not apply to adverbs "very" and those ending in "-ly."
Link compound proper nouns and adjectives with a hyphen. For example, "Italian-American."
Use a hyphen with numbers and fractions. For example, "four-fifths," "thirty-eight" and so on.
Separate double vowels with a hyphen that can sometimes occur with prefixes. The double vowel can sometimes be awkward. For example, "re-elect."
Use hyphens with other words with prefixes, such as "self-administer" and others.
Hyphenate compound words. There are certain words that are always hyphenated, like "water-repellent." Look up the word in a dictionary if you aren't sure. If the word is not hyphenated in the dictionary, it should be written as two words.
Use a hyphen in any instance where the meaning of a word might be unclear if no hyphen were used. For example, "She likes to read as recreation" versus "The director did an excellent job in the re-creation of the 1940s."