1. Which nouns? A sound masculine plural in iḍāfa to first-person yāʾ.
2. Which case markers? Estimated wāw in the nominative; yāʾ in the accusative and genitive.
3. Why does the form change? Loss of the plural nūn in iḍāfa; then the textbook’s explanation of wāw substitution, yāʾ assimilation, and ḍamma-to-kasra adjustment.
Try parsing all three original book examples aloud before starting the quiz.