While going over the correct prepositions to use with adjectives, I came across a situation I can't define. I'm using a Longman dictionary and a Cambridge grammar, but neither defines the difference between the two options.
e.g. I'm nervous about... my exams / doing something.
e.g. I'm nervous of... him / flying / dogs.
Now, I know that 'being nervous about one's exam' is not the same as 'being nervous of one's exam'. But how can I put the difference into words? Could I say that 'about' means one's nervous because of the exam and 'of' means one's almost afraid of the exam? I can't seem to find a better explanation.
On the other hand, we can say 'I'm nervous about / of flying', so how to explain that 'nervous of' and 'nervous about' can sometimes be interchangeable?