:This question really belongs on the Language Reference Desk, but I will offer that these expressions should be hyphenated "'only "'when they are used as non-predicative adjectives . ( That is, when they directly modify a noun and are not separated from the noun by a form of the verb " to be " . ) So, for example, " The can was upside down . " OR " I turned the can upside down . " BUT " I saw the upside-down can . " talk ) 17 : 16, 1 June 2011 ( UTC)
