Numbers in Arabic writing present two separate challenges. The first is stylistic: when do you spell a number out as a word and when do you write it as a digit? The second is grammatical: Arabic cardinal numbers from 3 to 10 have a famously counterintuitive gender agreement rule that trips up even advanced learners. This guide addresses both.
When to Spell Numbers Out as Words
| Context | Recommendation | Example |
|---|---|---|
| Numbers one and two | Always spell out | طالب واحد، كتابان اثنان |
| Numbers at the start of a sentence | Spell out | ثلاثة طلاب أجابوا... |
| Approximate or round numbers | Spell out | نحو عشرين شخصاً |
| Legal and formal documents | Spell out, then digit in parentheses | مئة وخمسون (١٥٠) ريالاً |
| Literary and narrative prose | Spell out (up to 100) | قرأتُ اثني عشر كتاباً |
When to Use Digits
| Context | Recommendation | Example |
|---|---|---|
| Statistics and data | Use digits | ٤٥٪ من المشاركين |
| Large numbers (100+) | Use digits | ٢٣٥ موظفاً |
| Dates and times | Use digits | في ٢٠٢٦ / الساعة ٩:٠٠ |
| Measurements with units | Use digits | ٥ كيلوغرام، ٣٠ متراً |
| Technical and scientific writing | Use digits | النسبة ٣:١ |
The Gender Polarity Rule (المخالفة)
This is the rule that confuses nearly everyone. Arabic cardinal numbers from 3 to 10 use gender polarity: the number takes the opposite gender form from the noun it is counting. This is called المخالفة (opposition or polarity).
| Counting masculine nouns | Counting feminine nouns |
|---|---|
| ثلاثةُ كتبٍ (3 books, كتاب is masc.) | ثلاثُ طالباتٍ (3 students, طالبة is fem.) |
| أربعةُ أبوابٍ (4 doors, باب is masc.) | أربعُ سياراتٍ (4 cars, سيارة is fem.) |
| خمسةُ رجالٍ (5 men) | خمسُ نساءٍ (5 women) |
Numbers 1 and 2
Numbers one and two are adjectives in Arabic, not quantifiers. They follow the noun and agree with it in gender normally (no polarity).
- كتابٌ واحدٌ (one book, masculine noun → masculine adjective)
- سيارةٌ واحدةٌ (one car, feminine noun → feminine adjective)
- كتابانِ اثنانِ (two books, the dual is used)
Numbers 11 and 12
Numbers 11 and 12 require the singular noun (not the plural) and show gender agreement (not polarity).
- أحدَ عشرَ كتاباً (11 books, singular كتاب, not plural)
- اثنا عشرَ كتاباً (12 books)
- إحدى عشرةَ سيارةً (11 cars, feminine)
Numbers 13 to 99
Numbers 13-19 use polarity on the units digit (same as 3-10) and agreement on the tens digit. The counted noun is always singular accusative.
| Number | With masculine noun | With feminine noun |
|---|---|---|
| 13 | ثلاثةَ عشرَ كتاباً | ثلاثَ عشرةَ سيارةً |
| 21 | واحدٌ وعشرون كتاباً | واحدةٌ وعشرون سيارةً |
| 100 | مئةُ كتابٍ (مضاف) | مئةُ سيارةٍ (مضاف) |
Common Number Mistakes
| ❌ Wrong | ✅ Correct | Error |
|---|---|---|
| ثلاث كتب | ثلاثة كتب | Missing ة with masculine noun |
| ثلاثة سيارات | ثلاث سيارات | Extra ة with feminine noun |
| عشرون كتاباً وواحد | واحدٌ وعشرون كتاباً | Units before tens in Arabic |
| كتبٌ واحد | كتابٌ واحدٌ | Wrong noun form (should be singular) |
Frequently Asked Questions
Why does ثلاثة end in taa marbuta when counting masculine nouns?
Arabic cardinal numbers 3-10 show gender polarity: the number takes the opposite gender marker from the noun. Masculine nouns get a number with ة (feminine ending). Feminine nouns get a number without ة (masculine form).
Should I use Eastern or Western Arabic numerals in formal writing?
Eastern Arabic numerals (١ ٢ ٣) are preferred in most Arab countries for formal print. In North Africa, Western Arabic numerals (1 2 3) are common. Online, both are widely accepted.