good-for nothing???

good-for nothing = 一無是處

her good- for nothing husband = 她一無是處的丈夫

good-for-nothing　三個字要有〔－〕相連（即hyphenated），變為一個字，不可分開．
意思係：無用的人;無益的東西(名詞) / 無用的;無益的 (形容詞)

例如：
Her boyfriend is a good-for-nothing. He only knows how to eat and sleep. (用作名詞)

This book is really good-for-nothing, I cant learn anything from it. (用作形容詞)

good-for nothing = useless 無效, 無用的.
例:
To punish a student by hitting is good for nothing.

good-for nothing 即係 無用/無益的

eg Chips is a kind of good for nothing food