● The following two rules apply to a noun when it becomes the muḍāf:
1. The muḍāf does not take al-: Al- can never be added at the beginning of the muḍāf.
2. The muḍāf has a light ending: Tanwīn is always removed from its final letter, leaving only one ḍammah, fatḥah, or kasrah.
● Study this chart showing the light endings of singular nouns and sound feminine plurals:
NominativeAccusativeGenitiveType
كِتَابُ (original: كِتَابٌ)كِتَابَ (original: كِتَابًا)كِتَابِ (original: كِتَابٍ)Masculine singular
جَنَّةُ (original: جَنَّةٌ)جَنَّةَ (original: جَنَّةً)جَنَّةِ (original: جَنَّةٍ)Feminine with tāʾ marbūṭah
آيَاتُ (original: آيَاتٌ)آيَاتِ (original: آيَاتٍ)آيَاتِ (original: آيَاتٍ)Sound feminine plural
أَبْوَابُ (original: أَبْوَابٌ)أَبْوَابَ (original: أَبْوَابًا)أَبْوَابِ (original: أَبْوَابٍ)Broken plural