I constantly need to remind myself of the grammar rules when dealing with numbers. Here’s my high level summary:

Numbers 1 and 2

  • Number:
    • Gender: Agrees with noun
    • Case: Agrees with noun
  • Noun:
    • Singular
    • Case: Depends on the role in the sentence
  • Note - the number is usually implied through the noun, so you don’t have to explicitly mention the number
  • (كتابٌ (واحدٌ
  • (قلمان (إثنان

Numbers 3 - 10

  • Number:
    • Gender: Disagrees with noun
    • Case: Depends on the role in the sentence
  • Noun:
    • Plural
    • Case: Genitive (majrūr), given the number is usually placed in an idāfa (noun following the number)
  • أربعةُ طلابٍ
  • عَشْرُ سياراتٍ

The counted noun for 11 - 99 is singular, in the acusative (mansūb), and will have a tanween unless stated otherwise

Number 11

  • Number:
    • Gender: Agrees with noun (both parts of the number)
    • Case: Accusative (mansūb) without tanween
  • Noun:
    • Singular
    • Case: Accusative (mansūb)
  • أحدَ عَشَرَ كتاباً
  • رأيتُ إحدى عشْرةَ سيارةَ

Number 12

  • Number:
    • Gender: Agrees with noun (both parts of the number)
    • Case: The first part of the number changes based on the role in the sentence
  • Noun:
    • Singular
    • Case: Accusative (mansūb)
  • إثْنا عَشرَ كتاباً - Twelve books
  • قرأتُ إثْنىْ عَشرَ كتاباً - I read twelve books
  • إثْنَتا عشرةَ رسالةً - Twelve letters
  • قرأتُ إثْنتىْ عَشرةَ رسالةَ - I read twelve letters

Numbers 13 - 19

  • Number:
    • Gender: The first part of the number agrees with the noun, the second part disagrees
    • Case: The first part of the number changes based on the role in the sentence
  • Noun:
    • Singular
    • Case: Accusative (mansūb)
  • خَمْسةَ عَشرَ أستاذاً - Fifteen teachers
  • سَبْعَ عَشرةَ طائرةً - Seventeen airplanes

Numbers 20 - 99

  • Number:
    • Gender: If the number ends in 1 or 2 (e.g. 21, 32, 41) then it agrees with the noun. The other numbers disagree with the noun. The tens part of the number doesn’t change with gender
    • Case: Depends on the role in the sentence
  • Noun:
    • Singular
    • Case: Accusative (mansūb)
  • لدي واحدٌ وعشرونَ كتابا
  • اشتريت هذا الكتاب بواحدٍ وعشرين جنيهًا
  • قرأت واحدًا وعشرين كتابًا
  • حضر الحفلَ خمسةٌ وعشرون مدعوًّا
  • له تسعٌ وتسعون نعجةً
  • سبعونَ ذراعًا

Numbers 100, 1000 (and multiples)

  • Number:
    • Gender: If the number ends in 1 or 2 (e.g. 21, 32, 41) then it agrees with the noun. The other numbers disagree with the noun.
    • Case: Depends on the role in the sentence. Note: 300, 400, 500 etc are themselves idafas so will be genitive (majrūr) - ثلاثُ مئةٍ, أَرْبَعُ مئةٍ
  • Noun:
    • Singular
    • Case: Genitive (majrūr), given it is the last item in an idafa
  • Note: 102 will form an idafa with the counted noun and will change case - مئتيْ رجلٍ
  • كان مقدارُهُ ألفَ سنةٍ
  • ثلاثةُ آلافِ مقاتلٍ!

Numbers 101 - 999

  • The case and gender rules follow the last numeral in the number (see below for two ways of saying 120)
  • خمسُمئةٍ وسبعةَ عشرَ رجلا
  • مئتان وخمسةُ كتبٍ
  • إلىَ مئة و عشرين درجةً
  • إلىَ عشرين و مئةِ درجةٍ