what is enough modifying in: Did I answer quickly enough?

[krishnap]

What is enough modifying in: Did I answer quickly enough?
My son says his teacher taught him in his online class that enough is modifying the simple predicate "Did ... answer".
I think it modifies the adverb quickly, and quickly modifies the simple predicate "Did ... answer"!
Can someone tell me whether I am right/wrong? Cannot find an exact answer after searching the web ... I would like to know for sure before confusing my son ...

 

[jutfrank]

Yes, you're right that enough modifies quickly.

The adverb phrase is quickly enough, which itself modifies answer.