Mā aḥsana Zaydan: mā + exclamatory verb + the object admired. Zaydan is the accusative object in the standard analysis.
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First Pattern: Basic Form
The Two Exclamatory Verbs: Forms, Rules and Parsing
Mā aḥsana Zaydan: mā + exclamatory verb + the object admired. Zaydan is the accusative object in the standard analysis.