فُعْلَيَانِ is the feminine dual pattern. When the singular ending -ā (alif maqṣūrah) enters the dual paradigm, a yāʾ becomes visible before the dual suffix.
كُبْرَى ← كُبْرَيَانِ — two bigger/greater feminine entities.
صُغْرَى ← صُغْرَيَانِ — two smaller feminine entities.
These are noun/adjective inflections of dual number, not imperfect or imperative verb conjugations. The source lists them as formal morphological slots.
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Feminine dual: fuʿlayāni
Ism al-Tafḍīl: Meaning, Eight Forms, Patterns and Use
فُعْلَيَانِ is the feminine dual pattern. When the singular ending -ā (alif maqṣūrah) enters the dual paradigm, a yāʾ becomes visible before the dual suffix.
كُبْرَى ← كُبْرَيَانِ — two bigger/greater feminine entities.
صُغْرَى ← صُغْرَيَانِ — two smaller feminine entities.
These are noun/adjective inflections of dual number, not imperfect or imperative verb conjugations. The source lists them as formal morphological slots.