However, some hyphenated compounds become closed compounds—teen-ager became teenager, for instance. Check a dictionary if you’re not sure how to spell a compound. Here are a few examples of common hyphenated compound words: Mother-in-law Half-pipe Ten-year-old Six-pack Foot-pound President...
An en dash should be used for clarity when one of the elements in a compound adjective is an open compound (made up of two words with a space between them) or when both elements contain hyphenated terms. In terms of clarity, this is especially helpful when one of the terms is a capit...