I checked out a Korean web site to find out a questionable sentence analysis.
See for yourself if it is done right.
http://hangulforest.com/gram_e.htm
그녀는 나쁜 사람이 아닙니다
The sentence is explained this way;
그녀는(subject) 나쁜 사람이(object) 아닙니다 (predicate)
If the sentence is analyzed for the English speaking people learning Korean, then, it should be analyzed closed to the English sentence structure.
I feel it should be done this way:
그녀는 (subject) 나쁜 사람이 (complement) 아닙니다 (Be verb)
She is not a bad person.
How can 'be verb' have an object?
What do you think?