Lesson 17
Rational vs Irrational Nouns and Broken Plural
جمع التكسير
Arabic has two types of plural: sound plural (سَالِم) which adds a suffix, and broken plural (تَكْسِير) which changes the internal vowel pattern. Broken plurals must be memorised they have no fixed rule.
Sound vs Broken Plural
SingularSound PluralBroken PluralMeaning
مُسْلِممُسْلِمُون—Muslim (m)
مُسْلِمَةمُسْلِمَات—Muslim (f)
كِتَاب—كُتُبbook
رَجُل—رِجَالman
مَسْجِد—مَسَاجِدmosque
بَيْت—بُيُوتhouse
وَلَد—أَوْلَادboy/child
Common Broken Plural Patterns
Although broken plurals cannot be predicted by rule, some patterns are very common. The two most productive: فُعُل (e.g. كُتُب from كِتَاب) and فِعَال (e.g. رِجَال from رَجُل). Learning the plural alongside the singular is essential.
PatternSingular exampleBroken plural
فُعُلكِتَابكُتُب
فِعَالرَجُلرِجَال
فُعُولبَيْتبُيُوت
أَفْعَالوَلَدأَوْلَاد
الْكُتُبُ عَلَى الطَّاوِلَةِ الرِّجَالُ فِي الْمَسْجِدِ الْبُيُوتُ كَبِيرَة
Al-kutubu ʿalā ṭ-ṭāwilati Ar-rijālu fī l-masjidi Al-buyūtu kabīra
The books are on the table. The men are in the mosque. The houses are big.
هَذِهِ الْكُتُبُ مُفِيدَةٌ هَؤُلَاءِ الرِّجَالُ مُجْتَهِدُون
Hādhihi l-kutubu mufīdatun Hāʾulāʾi r-rijālu mujtahidūn
These books are useful (f sg agreement). These men are hardworking (m pl agreement).
Sample Dialogue
أ: كَمْ كِتَاباً عِنْدَكَ؟ ب: عِنْدِي خَمْسَةُ كُتُبٍ. أ: وَكَمْ وَلَداً فِي الْفَصْلِ؟ ب: فِيهِ عَشَرَةُ أَوْلَاد.
A: Kam kitāban ʿindaka? B: ʿIndī khamsat kutubin. A: Wa-kam waladan fī l-faṣl? B: Fīhi ʿasharat awlād.
A: How many books do you have? B: I have five books. A: And how many boys are in the class? B: There are ten boys in it.
- Sound masculine plural: ـُون / ـِين. Sound feminine plural: ـَات. No internal change.
- Broken plurals change internal vowel structure learn each plural with its singular.
- Non-human broken plurals → feminine singular adjective/verb agreement: الْكُتُبُ كَثِيرَة.
- Human plurals (رِجَال، مُسْلِمُون) → masculine/feminine plural agreement applies normally.
- كَمْ؟ (kam = how many?) question for counting, followed by an accusative singular noun.