جِئْتُ أَنَا وَزَيْدًا
Translation: I came together with Zayd.
جِئْتُ: past verb built on sukūn; attached -tu is the subject in nominative position.
أَنَا: detached pronoun emphasizing -tu.
وَ: wāw of accompaniment.
زَيْدًا: accusative mafʿūl maʿahu with fatḥa.
The author also allows nominative zaydun here under a different analysis: the wāw then coordinates subjects.