The linking verb in this sentence is " was", predicate noun is faolon and the predicate adjective is "interrupted"
Explanation:
1. Linking verbs are those verbs in which there is no reference of action but just helps in connecting and linking the subject with the predicate in a given sentence. Examples include is, was, were, seem, are, am, look, feel sound, etc.
2. Verbs are basically considered to be action words but linking verbs do not talk bout action in a sentence rather it just assists in linking the first part of the sentence that is the subject, the doer in the sentence, with the predicate, which is what the subject does.
3. Predicate adjectives are those adjectives that transform and change the sentence which means that it doesn't rename the subject rather it describes it. In the above sentence," She was about to say more, but faolan interrupted", the word "interrupted" is the predicate adjective. A predicate is what the subject does and out here in the sentence the subject interrupted, hence it is predicate adjective. Here the predicate noun is faolon and what faolon did is predicate adjective, i.e, he interrupted.