Capable and able (to) are very similar in meaning, but not 100% the same. In today's post I am going to briefly go over the differences and point out common mistakes that are made when using them.
X: One man is able to destroy the world.
O: One man is capable of destroying the world.
Why is the first sentence incorrect? If someone is able to do something they can do it and it is not unusual for or surprising of them to do it. For example: "The doctor said I will be able to walk again after he fixes my broken leg." and "Will you be able to come over on Saturday?"
However if someone is capable of doing something then it means that it is possible for them to do it but is unusual for them to do it. "He's capable of cleaning his room, but he is very lazy." and "Ferrari's are capable of driving fast, but that is a little dangerous in downtown Tokyo."
