رَجُلٌ صَالِحٌ حَاضِرٌ — A righteous man is present.
رَجُلٌ: mubtadaʾ; صَالِحٌ: adjective; حَاضِرٌ: khabar.
In «الرَّجُلُ صَالِحٌ», by contrast, صَالِحٌ is the khabar. Case marking alone does not decide whether a word is an adjective or predicate: the intended predication matters.