1. The natural ability to do something well. English = talent.
2. A combination of a natural and acquired ability (through education, experience or training) to do something well. English = competence, skill.
3. The ability to speak, write or sign a language easily and correctly. English = fluency.
4. In education, the ability to use skills and knowledge to the level required of a workplace, and to be able to apply these skills and knowledge to new situations or environments. English = competency.