区别辨析 able, capable, competent, qualified

able, capable, competent, qualified 这些形容词均含有“有能力的、能干的”之意。

able：最常用词，多用于褒义，表示能力在实际表现中高于平均水平，着重指多方面的、经常性的或潜在性的能力。有时也指高超、非凡的能力。

• the ablest student in the class
  班上最有才华的学生
• With enough practice, machines may be able to recognise these implicit cues and thus display the equivalent of good judgment.
  经过足够多的训练，机器或许能够识别这些隐含的线索，从而展示出某种相当于良好判断力的东西。
  ——《经济学人》

capable：语气弱于 able ，指有能力、有潜力或有条件做某事，常与 of 连用，强调具有适合工作的素质，但与能力是否杰出无关。

• Yet they have never looked capable of producing the decisive change in China’s economic model that many in Washington crave.
  但他们似乎总也无力让中国经济模式产生华盛顿许多人所渴望的那种决定性变化。
  ——《经济学人》
• 中国共产党和中国人民以英勇顽强的奋斗向世界庄严宣告，中国人民不但善于破坏一个旧世界、也善于建设一个新世界，只有社会主义才能救中国，只有社会主义才能发展中国！
  Through tenacious struggle, the Party and the Chinese people showed the world that the Chinese people were capable of not only dismantling the old world, but also building a new one, that only socialism could save China, and that only socialism could develop China.
  ——习总书记在庆祝中国共产党成立100周年大会上的讲话（双语全文）

competent 和 qualified 都意味着拥有足够的经验、技能、训练或其它所需的条件，以胜任某项工作或者达到足够的绩效。

• 建设高素质专业化干部队伍。
  Training a contingent of competent and professional officials.
  ——党的十九大报告（双语全文）
• 完善干部考核评价体系，引导干部树立和践行正确政绩观，推动干部能上能下、能进能出，形成能者上、优者奖、庸者下、劣者汰的良好局面。
  We will improve the system for assessing officials’ performance and see that officials have a correct understanding of what it means to perform well. We should also see that officials can be demoted as well as promoted and dismissed as well as recruited, thereby creating an environment in which the competent are elevated, the outstanding are rewarded, the mediocre are demoted, and the incompetent are dismissed.
  ——党的二十大报告（双语全文）