Negative Clause: Accusative Parsing

Al-Mustathnā: Connected and Disconnected Exceptions, Four Case Rules

«مَا جَاءَنِي أَحَدٌ إِلَّا زَيْدًا»
mā: negation.
jāʾanī: past verb plus object pronoun.
aḥadun: nominative subject and exception base.
illā: exception particle.
Zaydan: accusative exception with fatḥah.

Negation permits the accusative; it does not require substitution.