Hyphen (-)

■ Use a hyphen whenever two or more words are joined together to serve as an adjective directly before a noun (unless the first word ends in -ly). → The well-regarded teacher was honored for his exceptionally hard work and dedication.
■ Use a hyphen when writing out fractions and compound numbers. → I spent one-third of my allowance on books and DVDs.
■ Use a hyphen with compound nouns. → My sister-in-law works at the local mall.

English to the Max: 1, 200 Practice Questions That Will Maximize Your English Power, Learning Express LLC, 2008, p.7