able ـــcapableــAbility

She is an able teacher. She is a teacher with quality

She is a capable teacher.  She has the ability to be a teacher   able  -  if someone or something is able to do something, they have skills or qualities which make it possible for them to do it  capable - if a person or thing is capable of doing something, they have the ability, capacity, or potential to do it  Ability can be acquired through a series of training, but capability has nothing to do with training  I do not doubt his ability to do the work