The mudaf ilayh may be definite in several ways:
- Proper name: كِتَابُ زَيْدٍ
- Pronoun: كِتَابُهُ
- Demonstrative: كِتَابُ هٰذَا
- Relative construction: كِتَابُ الَّذِي نَصَرْتُهُ
- Noun with ال: كِتَابُ الْوَلَدِ
In each case, the mudaf points to a definite possessor or referent.