أَقَامَ زَيْدٌ أَمْ لَا
Did Zayd stand up, or not?
“Am lā” explicitly presents the two possibilities: the relation occurred, or it did not. The speaker is not asking which other person or thing is involved, but whether the event happened.
The presence of am alone therefore does not force a taṣawwur reading. Determine whether the alternatives name two candidates or the positive and negative states of one relation.