وَالْأَسْبَابُ التِّسْعَةُ هِيَ: الْعَدْلُ، وَالْوَصْفُ، وَالتَّأْنِيثُ، وَالْمَعْرِفَةُ، وَالْعُجْمَةُ، وَالْجَمْعُ، وَالتَّرْكِيبُ، وَالْأَلِفُ وَالنُّونُ الزَّائِدَتَانِ، وَوَزْنُ الْفِعْلِ.
Translation: The nine causes are ʿadl (altered form), description, femininity, definiteness, foreign origin, a particular plural pattern, compounding, additional alif and nūn, and a verb pattern.
These nine headings each operate under specific conditions.