Arabic Number Grammar: The Reverse Agreement Rule Explained
Arabic number grammar has a reputation, and it is earned: the numbers 3 through 10 take the opposite gender of the noun they count. Three books is ثَلَاثَةُ كُتُبٍ with a feminine-looking number, while three cars is ثَلَاثُ سَيَّارَاتٍ with a masculine-looking one. Native speakers of many dialects simplify this in everyday speech, but in Modern Standard Arabic and the Quran the classical rules apply in full.
The system is actually very regular once you split it into four zones: 1–2, 3–10, 11–99, and the hundreds and thousands. Each zone has one rule for gender and one rule for the form of the counted noun. This guide walks through all four zones with fully voweled examples, including some straight from the Quran, where number phrases like أَحَدَ عَشَرَ كَوْكَبًا (eleven stars) showcase the rules perfectly.
One and Two: Normal Agreement
The numbers 1 and 2 are the easy zone: they behave like ordinary adjectives, following the noun and agreeing with it in gender. كِتَابٌ وَاحِدٌ (one book) and سَيَّارَةٌ وَاحِدَةٌ (one car). In practice you often omit them entirely, since a singular noun already means one of something.
For two, Arabic usually just uses the dual ending: كِتَابَانِ (two books), سَيَّارَتَانِ (two cars). The words اِثْنَانِ (masculine) and اِثْنَتَانِ (feminine) are added after the dual only for emphasis: كِتَابَانِ اثْنَانِ (two books, exactly two). So in this zone, masculine goes with masculine and feminine with feminine — no reversal yet.
Three to Ten: Reverse Gender, Genitive Plural
Here is the famous rule. From 3 to 10, the number takes the opposite gender of the counted noun, and the noun appears in the genitive plural. Crucially, the gender that matters is the gender of the noun's singular form, not its plural. كِتَاب (book) is masculine, so its number takes the feminine-looking tāʾ marbūṭa: ثَلَاثَةُ كُتُبٍ. سَيَّارَة (car) is feminine, so its number drops the tāʾ marbūṭa: ثَلَاثُ سَيَّارَاتٍ.
A reliable mental shortcut: if the singular noun ends in ة, the number does not, and vice versa. The Quran applies this throughout — سَبْعَ سَمَاوَاتٍ (seven heavens: سَمَاء is feminine, so سَبْع has no ة) and أَرْبَعَةَ أَشْهُرٍ (four months: شَهْر is masculine, so أَرْبَعَة carries the ة). The number itself takes whatever case the sentence requires, and the noun after it is always genitive plural in this zone.
Eleven to Nineteen: Compounds and the Accusative Singular
From 11 upward, the counted noun switches to the accusative singular — grammatically a tamyīz (specification). So eleven stars is أَحَدَ عَشَرَ كَوْكَبًا, exactly as in the Quranic verse إِنِّي رَأَيْتُ أَحَدَ عَشَرَ كَوْكَبًا (indeed I saw eleven stars): singular كَوْكَبًا with tanwīn fatḥ, not a plural.
Within 11 and 12, both parts of the compound agree with the noun's gender: أَحَدَ عَشَرَ رَجُلًا (eleven men) but إِحْدَى عَشْرَةَ امْرَأَةً (eleven women); اِثْنَا عَشَرَ شَهْرًا (twelve months) but اِثْنَتَا عَشْرَةَ عَيْنًا (twelve springs — a Quranic phrase). From 13 to 19, the compound splits: the units digit reverses gender as in the 3–10 rule, while عَشَرَ/عَشْرَةَ agrees with the noun. So thirteen books is ثَلَاثَةَ عَشَرَ كِتَابًا and thirteen cars is ثَلَاثَ عَشْرَةَ سَيَّارَةً. These compounds are fixed on fatḥa in every case, except that the اِثْنَا of 12 declines like a dual (اِثْنَيْ عَشَرَ in the accusative and genitive).
Twenty to Ninety-Nine: The Tens Don't Care About Gender
The tens — عِشْرُونَ (20), ثَلَاثُونَ (30), أَرْبَعُونَ (40), and so on — have a single form for both genders and decline like sound masculine plurals: عِشْرُونَ in the nominative, عِشْرِينَ in the accusative and genitive. The counted noun stays accusative singular: عِشْرُونَ طَالِبًا (twenty male students), عِشْرُونَ طَالِبَةً (twenty female students). The Quranic أَرْبَعِينَ لَيْلَةً (forty nights) shows the accusative tens with a feminine noun.
For compound numbers like 25, the unit comes first, joined by وَ, and the unit follows its own zone's rule: خَمْسَةٌ وَعِشْرُونَ كِتَابًا (twenty-five books — masculine noun, so the unit خَمْسَة takes ة) versus خَمْسٌ وَعِشْرُونَ سَيَّارَةً (twenty-five cars). The noun remains accusative singular all the way to 99.
Hundreds and Thousands: Genitive Singular
مِائَة (100, often spelled مِئَة and always pronounced miʾa) and أَلْف (1000) take the counted noun in the genitive singular, as the second term of an iḍāfa: مِائَةُ كِتَابٍ (a hundred books), أَلْفُ سَنَةٍ (a thousand years). مِائَة itself does not change for the noun's gender: مِائَةُ رَجُلٍ and مِائَةُ امْرَأَةٍ both use the same form.
Multiples follow suit: ثَلَاثُمِائَةٍ (300), أَلْفَا سَنَةٍ (2000 years, dual of أَلْف), ثَلَاثَةُ آلَافٍ (3000 — note أَلْف is masculine, so 3–10 reversal applies to آلَاف). The Quran's مِائَةَ عَامٍ (a hundred years) and أَلْفَ سَنَةٍ إِلَّا خَمْسِينَ عَامًا (a thousand years less fifty) pack three of these rules into a few words: genitive singular after 100 and 1000, and accusative singular after the tens.
A Cheat Sheet and How to Drill It
The whole system compresses into four lines. 1–2: number agrees, follows the noun. 3–10: number reverses gender, noun genitive plural. 11–99: noun accusative singular; 11–12 agree fully, 13–19 reverse only the unit, tens are genderless. 100 and 1000: noun genitive singular.
Reading about it is not the same as producing it under time pressure, though. Fahm's numbers section drills counting with real nouns so the ة-flipping becomes reflex, and the grammar course lesson on numbers 1–10 and counting rules walks through this zone by zone with exercises. Five minutes a day of counting real objects — ثَلَاثَةُ أَقْلَامٍ، أَرْبَعُ نَوَافِذَ — beats an hour of staring at the table.
Frequently asked questions
Why do Arabic numbers 3–10 reverse gender?
It is an inherited feature of Semitic languages — Hebrew does the same thing. Historically the -at ending on numbers may not have been a feminine marker at all, but in the modern language you simply learn it as polarity: the number takes the opposite gender of the counted noun's singular.
Which gender do I check if the plural looks feminine?
Always the singular. صَفَحَات (pages) looks feminine and its singular صَفْحَة is feminine, so: ثَلَاثُ صَفَحَاتٍ. But a masculine noun with a broken plural like كُتُب still counts as masculine because كِتَاب is masculine: ثَلَاثَةُ كُتُبٍ.
Why is the noun singular after 11–99 when the meaning is plural?
Grammatically it is a tamyīz (accusative of specification): the number phrase is complete on its own and the singular noun specifies what is being counted, as if saying twenty, in terms of student. That is why it takes tanwīn fatḥ: عِشْرُونَ طَالِبًا.
Do native speakers really apply all these rules when speaking?
In spoken dialects the system is heavily simplified, and even educated speakers slip in fast MSA speech. But in written MSA, formal speech, news broadcasts, and the Quran, the full rules apply — so you need them for reading and writing even if conversation is more forgiving.
Fahm covers this with interactive lessons, spaced repetition, and quizzes — start free, no account needed.
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