able: suggests ability above the average as revealed in actual performance: proved that she is an ~ Shakespeare actress.


capable: stresses the having of qualities fitting one for work, but does not imply outstanding  qualities: ~ of doing simple tasks under supervision.


competent and qualified:implies having the experience or training for adequate performance: a leap that any ~(competent) ballet dancer can execute; seek help from a ~(qualified) medical professional.


able能力: 超过常人的能力，capable能力: 强调能适应工作但不表示出众，competent,qualified称职的: 表示具备经验和训练  


记忆方法: 1）CACQ长安长全<==足够的能力才能长久的安全。


         2) able和ability表示超过常人的能力，和capable不同。


         3）能力的意思是能适应工作meanhaving power or fitness for work