To Hyphenate or Not to Hyphenate
Knowing When to Hyphenate Compound Words
This articles provides a few rules regarding the hyphenation of compound words.
One of the most common spelling issues involve compound words. Writers are not always sure whether to spell a compound word as a single word, two or more separate words, or as a hyphenated term. While consulting a dictionary is usually the best answer, some of these words are not necessarily found in dictionaries, and in a few cases, even if they are the spellings vary. There is also no definitive collection of rules regarding the hyphenation of compound words, so consulting the manual of style appropriate for the industry you write for may at least provide a guideline. However, if you don't have one available, keep the following rules in mind.
Permanent Compounds
Permanent compounds are so frequently used that they have been accepted into the general vocabulary. Compound words such as prime minister, headache, high school, city-state, and others are examples of permanent compounds. Many are so common that most writers will know whether to hyphenate them, separate them, or write them as one word. If there is any question about how to spell them, you can find them in a dictionary. Just be certain your dictionary is current.
Temporary Compounds
A temporary compound is a combination created for a specific purpose. Many of these temporary compounds serve as adjectives or adverbs called compound modifiers, adjectival or adverbial phrases of two or more words. When a compound modifier appears before the word, the compound modifier is often hyphenated to prevent misunderstanding, like much-needed clothing. Hyphenating the the compound modifier in this phrase clarifies that the clothing is needed badly and not abundant but also needed. However, if the compound modifier appears after the the term, the words are not hyphenated (the clothing was much needed).
Hyphenation is usually not used for adverb-adjective and noun-noun compound modifiers when ambiguity regarding meaning is not possible. For instance, with the phrase wholly owned subsidiary, confusion as to its meaning is unlikely since wholly clearly modifies the adjective owned and not the noun subsidiary.
Many permanent compounds started out as temporary compounds but become so widely used that they are accepted as permanent and included in the dictionary.
Final Comments
A manual of style will provide a more comprehensive rules for the hyphenation of compound words, but even these rules have their exceptions. Also, even the most current dictionaries will often not include some of the widely-used compound words (even some of the newer permanent ones), leaving the writer struggling with questions regarding the spelling of compound words.
