Most Not Hyphenated
Most compound nouns are not hyphenated:
master builder fellow employee attorney general
Complete Words
Others have migrated and become complete words, spelled as one word, with no hyphen:
headache checkbook boardinghouse clearinghouse
For variations of these compound nouns, e.g., rest house, reference book, always check the dictionary for proper spelling.
Hyphenated Compound Nouns
Some compound nouns are hyphenated:
vice-president scholar-poet, student-athlete brother-in-law great-granddaughter (hyphenate all great relatives) self-restraint (hyphenate all the -self compounds) one-half president-elect
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