جِئْتُ وَزَيْدًا
Translation: I came with Zayd.
جِئْتُ: past verb built on sukūn; the suffix -tu is the subject.
وَ: wāw of accompaniment.
زَيْدًا: accusative accompaniment complement.
The restriction in this book’s formulation matters: direct coordination with the attached subject pronoun is not admitted here. Do not automatically replace the accusative with a nominative.