failure(失敗) 和 success(成功)是一對反義詞，但用法上有不少相似之處和需注意之處：
1. 泛指一般意義的“失敗”或“成功”，通常是不可數名詞；指具體的失敗(成功)的人或事等，或指一次失敗或成功等，通常是可數名詞。如：
Failure is the mother of success. 失敗是成功之母。
If you fail, make failure a stepping stone to success. 假若你失敗，就把它當作通向成功的墊腳石。
Success came after many failures. 多次失敗之后，終于獲得了成功。
He is a failure (success) in business. 他在生意上很失敗(成功)。
It was said that the party was a failure (success). 據說晚會開得不成功(很成功)。
2. 表示未能做某事，通常用 one’s failure to do sth；表示成功地做了某事，通常用 have success in doing sth。如：
His failure to help us was disappointing. 他未能幫助我們真是令人失望。
Did you have any success in persuading her to come? 你說服了她來嗎?
表示在某一方面的失敗或考試不及格等，可用介詞 in。如：a failure in duty(失職)，failure in love(失戀)，one’s failure in an exam(考試不及格)