It is not a predicate adjective, but a partitive genitive after hwt.
In some of these examples, the predicate adjective has a modifier.
A predicate adjective completes the meaning of the predicate verb, but describes or limits the subject.
Before a predicate adjective que should be translated by ‘how.’
The past participle is often used as a predicate adjective expressing state or condition.
In the second, the participle drenched expresses mere condition, and is therefore a predicate adjective.
An adjective in the predicate belonging to a noun or pronoun in the subject is called a predicate adjective.
an adjective following a linking verb that describes the subject, such as 'roses are red'