worthwhile
Pronunciation: /wəːθˈwʌɪl/
adjective

When the adjective worthwhile is used attributively (i.e. before the noun) it is always written as one word: a worthwhile cause. However, when it is used predicatively (i.e. it stands alone and comes after the verb) it may be written as either one or two words: we didn’t think it was worthwhile/worth while.