
David Y. answered 09/21/20
English (Language Arts) reading/writing/editing specialist.
Denise,
Remember that the predicate is essentially the verb. In the example you gave, "is challenging" is the predicate (verb) of the sentence. The word 'challenging' is not used as an adjective. It is a verb that is "linked" to the word 'is' which is a linking verb. Hope this helps.