The hyphen may be the least-thought-about form of punctuation, but it is very important. Hyphens are joiners; here’s how to use them.

Hyphens are used to link compound modifiers. 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. Examples: a full-time job, the well-known author, the reddish-brown house, the as-yet-unannounced proposal, the team is second-rate, the 4-year-old girl. However, this rule does not apply to adverbs like “very” and those ending in -ly: a very tall man, the quickly moving car.

Hyphens are used to link compound proper nouns and adjectives. Hyphenate constructions like African-American, Chinese-American and others when they are used as nouns or adjectives.

Hyphens are used with numbers and fractions. Twenty-five, one-fourth, sixty-eight. Other issues involving numbers: the 2-1 vote, the 20-to-1 odds.

Hyphens are used to separate double vowels occurring with prefixes. Use a hyphen in certain instances where prefixes are added to words and a confusing double vowel occurs. For example, re-examine, anti-immigration.

Hyphens are also used with other prefixes: socio-economic, self-help and others.

Hyphens are used with compound words. Some words are typically hyphenated, like water-repellent. Use a dictionary for help. If a word is not in the dictionary, it most often should be treated as two words.

Hyphens help writers avoid ambiguity. Use a hyphen in any instance where the usage would be ambiguous if the hyphen were omitted. For example: She recovered from her cold. She re-covered the pot of boiling water. Swimming is a good form of recreation. The re-creation of war was accurately portrayed in the novel.

Don't forget about suspending hyphens. Follow this form: The camp is for 10- to 12-year-olds.