unsuccessful in [noun/gerund]
She was unsuccessful in her attempt to fix the computer.
她修理电脑的尝试不成功。
不成功的；失败的
失败的,不成功的。
失败的,不成功的。
Failed, not successful.
He made an unsuccessful attempt to open the locked door.
他试图打开那扇锁着的门，但没有成功。
用法提示：此处 unsuccessful 是形容词，作定语修饰 attempt，意为“不成功的”。
The experiment was unsuccessful because the equipment failed.
实验没有成功，因为设备出了故障。
用法提示：此处 unsuccessful 是形容词，作表语，表示“不成功的、失败的”。
The committee considered the negotiations unsuccessful and decided to try again.
委员会认为谈判不成功，决定再试一次。
用法提示：此处 unsuccessful 是形容词，作宾语补足语，表示“不成功的”。
She was unsuccessful in her attempt to fix the computer.
她修理电脑的尝试不成功。
He made an unsuccessful bid for the presidency.
他竞选总统失败。
They were unsuccessful at finding a solution.
他们未能找到解决方案。
常用于修饰具体尝试或项目；语气直接
强调努力后无结果；书面语
语气强，暗示完全无望；常指行动本身无意义
多用于修饰努力或尝试；较正式
中性词，指缺乏产出；可用于工作、会议等
grammar · medium
易错句子I unsuccessful in the exam.
正确表达I was unsuccessful in the exam.
“unsuccessful”是形容词，不能单独作谓语，需加系动词“be”构成系表结构。
grammar · medium
易错句子He was unsuccessful to pass the test.
正确表达He was unsuccessful in passing the test.
形容词“unsuccessful”后接动词时，需用介词“in”加动名词形式，而不是动词不定式。
直接反义词，表示达到预期目标
指在竞争或斗争中获胜
强调巨大成功或胜利后的自豪
指经济或事业上的持续成功
指通过努力达到高水平
unsuccessful 是形容词，修饰名词；unsuccessfully 是副词，修饰动词或句子。
unsuccessful 强调结果不成功，failed 更常用于表示尝试后失败，也可作动词过去式。注意形容词用法时，failed 常置于名词前（如 failed attempt）。
unsuccessful 指未能达到预期目标，ineffective 强调没有产生预期效果或效率低，多形容方法、药物等。
不成功的尝试
He made an unsuccessful attempt to climb the mountain.
他尝试爬山，但没有成功。
竞标失败
The company's unsuccessful bid for the contract was disappointing.
这家公司竞标合同失败，令人失望。
搜索无果
After an unsuccessful search, they gave up looking for the lost key.
经过一番搜索无果后，他们放弃了寻找丢失的钥匙。
失败的结果
The unsuccessful outcome of the experiment led to a new approach.
实验失败的结果促使他们采用了新方法。
落选者
The unsuccessful candidate thanked his supporters after the election.
落选者在选举后感谢了他的支持者。
手术失败
The unsuccessful operation required further treatment for the patient.
手术失败后，患者需要进一步治疗。
Dictionary facts from ECDICT, WIKTIONARY.