Are “inept” and “incompetent” synonyms?

Sometimes I use the word “incompetent” describe someone who is, typically, in over their head and not smart enough to at least know they are in over their head. But a friend recently used the word “inept” to describe such a person.

To me, “inept” refers to someone who is physically incompetent. Like a basketball player that can’t play the game — yet is somehow in the game — is inept in my mind. And someone who is incompetent can be incompetent in many ways, physically and even logically.

So are “inept” and “incompetent” interchangeable synonyms? Or is there more subtlety to their use?

Solution 1:

Incompetent implies inability (“not up to the job”) whereas inept could be a judgement on something not being done well on a particular occasion. For example it would not be a contradiction to say:

“No one disputes Charlie’s competence in managing his employees, but his handling of the dispute between John and James was manifestly inept.”