“A-qāma Zaydun?” questions whether Zayd’s standing/coming occurred and thus seeks taṣdīq. “A-Zaydun qāma am ʿAmrun?” treats the event as given and asks which person performed it: taṣawwur.
The mere presence of a question mark is not enough. Proper rhetorical analysis identifies the missing information—the relation’s truth, or the identity of a component.
FeatureTaṣawwurTaṣdīq
TargetIdentify a componentDetermine if relation obtains
ExampleA-dibs ... am ʿasal?A-qāma Zayd?
AnswerSyrup / honeyYes / no
Question focusAn elementThe proposition