successful的反義詞

successful詞性是形容詞

釋義：something that is successful achieves what it was intended to one is successful achieves what they intended to achieve.有成效的

例句 How successful will this new treatment be? 這種新療法將會有多大成效?

successful的反義詞是unsuccessful

釋義：Something that is unsuccessful does not achieve what it was intended to achieve. 不成功的

例句：His efforts were unsuccessful.他的努力沒有成功。

successful是成功的意思所以反義詞是失敗可以是fail還有unsuccessful這個詞，也是不成功，失敗的意思可以使用