Full Parsing of the Verbal-Clause Predicate

Types of Khabar and the Linking Pronoun

زَيْدٌ: nominative mubtadaʾ.
قَامَ: past-tense verb built on fatḥ.
أَبُوهُ: verb’s subject, nominative by wāw; «ـهُ» is the genitive possessor and referential link to Zayd.
قَامَ أَبُوهُ: whole verbal clause, in the nominative syntactic position of Zayd’s predicate.

Zayd is not the grammatical subject of «قَامَ» here; «أَبُوهُ» is.