Noun Declension Rules (الإعراب)

Arabic nouns decline for case (nominative, accusative, genitive), definiteness, number, and gender. ACE’s noun analyzer uses dedicated declension arrays for singular, dual, plural, and broken plural patterns.

1. Cases

• Nominative (مرفوع) — ُ
• Accusative (منصوب) — َ
• Genitive (مجرور) — ِ

2. Definiteness

• Definite: ال + case vowel
• Indefinite: tanwīn (un / an / in)

3. Dual Nouns

• Nom.: -انِ
• Acc./Gen.: -يْنِ

4. Sound Masculine Plural

• Nom.: -ونَ
• Acc./Gen.: -ينَ

5. Sound Feminine Plural

• -اتُ (nom.)
• -اتِ (acc./gen.)

6. Broken Plurals

Irregular internal patterns such as:

• كِتَاب → كُتُب
• رَجُل → رِجَال
• بَيْت → بُيُوت

7. Possessive Pronouns with Nouns

• كِتَابُهُ — his book
• كِتَابُنَا — our book

ACE treats noun declension separately from verb parsing and uses case suffixes only in noun tenses (15–23).