The active participle of a hollow-yāʾ root follows the فَاعِلٌ pattern. Leaving the original yāʾ unchanged after the long alif would produce the intermediate form; the relevant morphological rule replaces that yāʾ with hamzah.
ب ي ع → بَايِعٌ → بَائِعٌ.
بَائِعٌ — seller (masculine).
بَائِعَةٌ — seller (feminine).
The visible hamzah does not imply a root ب أ ع. The root remains ب ي ع, and the hamzah is explained by the participial pattern.
Opening interactive controls...
Why the Active Participle Contains Hamzah
Complete Paradigms of the Hollow Yāʾ Verb: Bāʿa–Yabīʿu
The active participle of a hollow-yāʾ root follows the فَاعِلٌ pattern. Leaving the original yāʾ unchanged after the long alif would produce the intermediate form; the relevant morphological rule replaces that yāʾ with hamzah.
ب ي ع → بَايِعٌ → بَائِعٌ.
بَائِعٌ — seller (masculine).
بَائِعَةٌ — seller (feminine).
The visible hamzah does not imply a root ب أ ع. The root remains ب ي ع, and the hamzah is explained by the participial pattern.