Numbers thirteen through nineteen contain two gender decisions that point in opposite directions. The first component—three through nine—shows polarity, taking the form opposite the counted noun's gender. The second component—عشر/عشرة—agrees with the noun. The complete compound is fixed in form, and the counted noun is a singular accusative specification: ثلاثة عشر طالبا “thirteen male students,” but ثلاث عشرة طالبة “thirteen female students.”
This split is genuinely demanding because English gives no comparable signal. Learn each number phrase as a three-part structure: opposite unit + agreeing ten + singular accusative noun. These forms are standard MSA (formal); everyday regional speech often simplifies endings and may use local forms (regional: varies).
Eleven and twelve do not use this split rule; compare their full agreement and the special case forms of twelve on Numbers 11 and 12.
The split gender rule
With a masculine counted noun, the unit has ـة and ten is عشر. With a feminine counted noun, the unit lacks ـة and ten is عشرة.
| Value | With masculine طالب | With feminine طالبة |
|---|---|---|
| 13 | ثلاثة عشر طالبا | ثلاث عشرة طالبة |
| 14 | أربعة عشر طالبا | أربع عشرة طالبة |
| 15 | خمسة عشر طالبا | خمس عشرة طالبة |
| 16 | ستة عشر طالبا | ست عشرة طالبة |
| 17 | سبعة عشر طالبا | سبع عشرة طالبة |
| 18 | ثمانية عشر طالبا | ثماني عشرة طالبة |
| 19 | تسعة عشر طالبا | تسع عشرة طالبة |
انضم ثلاثة عشر مهندسا إلى البرنامج.
ʾinḍamma thalāthata ʿashara muhandisan ʾilā l-barnāmaj.
Thirteen engineers joined the program.
Singular مهندس is masculine. The unit therefore shows polarity as ثلاثة, while agreeing ten is عشر. The specification مهندسا is singular accusative.
وصلت ثلاث عشرة رسالة قبل الموعد.
waṣalat thalātha ʿashrata risālatan qabla l-mawʿid.
Thirteen messages arrived before the deadline.
Singular رسالة is feminine. The unit is the opposite form ثلاث, while عشرة agrees. Notice that “opposite” does not apply to both components.
The specification is singular accusative
Although the English noun is plural, Arabic uses one indefinite singular after 13–19. This word is the tamyīz, the specification that identifies what the compound number counts.
طلبت خمسة عشر كتابا للمكتبة.
ṭalabtu khamsata ʿashara kitāban li-l-maktaba(h).
I ordered fifteen books for the library.
أجرت الشركة أربع عشرة مقابلة خلال يومين.
ʾajrati sh-sharikatu ʾarbaʿa ʿashrata muqābalatan khilāla yawmayn.
The company conducted fourteen interviews over two days.
In خمسة عشر كتابا, masculine كتاب selects polarity-marked خمسة plus agreeing عشر. In أربع عشرة مقابلة, feminine مقابلة selects أربع plus عشرة. Both counted nouns remain singular accusative.
If an adjective follows the specification, it agrees with that singular noun and shares its accusative case.
استقبل المركز ست عشرة حالة جديدة هذا الصباح.
ʾistaqbala l-markazu sitta ʿashrata ḥālatan jadīdatan hādhā ṣ-ṣabāḥ.
The center received sixteen new cases this morning.
جديدةً is feminine singular accusative because it describes حالةً, not the abstract plurality of sixteen cases.
The compound does not decline for case
Numbers 13–19 are compounds built on fatḥ. Their spoken form stays the same whether the whole number phrase is nominative, accusative, or genitive. The grammatical position changes; the compound's surface form does not.
افتتح أربعة عشر فرعا هذا العام.
ʾuftutiḥa ʾarbaʿata ʿashara farʿan hādhā l-ʿām.
Fourteen branches were opened this year.
زار المدير أربعة عشر فرعا في أسبوع واحد.
zāra l-mudīru ʾarbaʿata ʿashara farʿan fī ʾusbūʿin wāḥid.
The director visited fourteen branches in one week.
يعمل الفريق في أربعة عشر فرعا إقليميا.
yaʿmalu l-farīqu fī ʾarbaʿata ʿashara farʿan ʾiqlīmiyyā.
The team works in fourteen regional branches.
The first phrase is nominative, the second accusative, and the third genitive after في. In all three, أربعة عشر remains ʾarbaʿata ʿashara. The singular specification remains accusative فرعا, even after a preposition governing the whole phrase.
Eighteen and the defective form of eight
Eight has an irregular form with feminine counted nouns. In eighteen, use ثمانية عشر before a masculine noun but ثماني عشرة before a feminine noun. The retained ي is part of the correct first component.
سجل التطبيق ١٨ شكوى، أي ثماني عشرة شكوى، في ساعة واحدة.
sajjala t-taṭbīqu thamāniya ʿashrata shakwā, ʾay thamāniya ʿashrata shakwā, fī sāʿatin wāḥida(h).
The app recorded 18 complaints—that is, eighteen complaints—in one hour.
Feminine شكوى selects polarity-marked ثماني plus agreeing عشرة. شكوى is a singular accusative noun ending in ى; its case vowel is not visible in ordinary spelling. The digit sequence ١٨ keeps normal place value inside right-to-left Arabic text.
Prices, measures, and statistics
The same structure operates in practical numerical information. Currency and units do not create a special “measurement plural.”
بلغت رسوم التسجيل سبعة عشر دولارا.
balaghat rusūmu t-tasjīli sabʿata ʿashara dūlārā.
The registration fee came to seventeen dollars.
Masculine دولار takes سبعة عشر, then appears singular accusative. Even though رسوم is plural, it does not control the numeral: the counted unit دولار does.
شملت الدراسة تسع عشرة دولة من المنطقة.
shamilati d-dirāsatu tisʿa ʿashrata dawlatan mina l-minṭaqa(h).
The study included nineteen countries from the region.
Common Mistakes
Making both parts show polarity
❌ حضر ثلاثة عشرة طالبا.
Incorrect — the first part shows polarity, but عشر must agree with masculine طالب.
✅ حضر ثلاثة عشر طالبا.
ḥaḍara thalāthata ʿashara ṭālibā.
Thirteen students attended.
Making both parts agree
❌ وصلت ثلاثة عشرة رسالة.
Incorrect — feminine رسالة requires polarity-marked ثلاث as the first component.
✅ وصلت ثلاث عشرة رسالة.
waṣalat thalātha ʿashrata risāla(h).
Thirteen messages arrived.
Using a plural specification
❌ طلبت خمسة عشر كتبا.
Incorrect — 13–19 take a singular accusative specification.
✅ طلبت خمسة عشر كتابا.
ṭalabtu khamsata ʿashara kitābā.
I ordered fifteen books.
Dropping the irregular ي in feminine eighteen
❌ سجلنا ثمان عشرة شكوى.
Incorrect in formal MSA — before feminine شكوى, eighteen begins with ثماني.
✅ سجلنا ثماني عشرة شكوى.
sajjalnā thamāniya ʿashrata shakwā.
We recorded eighteen complaints.
Reversing a two-digit numeral
❌ الرقم ١٧ يعني واحدا وسبعين.
Incorrect — right-to-left layout does not turn 17 into 71.
✅ الرقم ١٧ يعني سبعة عشر.
ar-raqmu sabʿata ʿashara yaʿnī sabʿata ʿashar.
The number 17 means seventeen.
Key Takeaways
- In 13–19, the unit shows polarity but عشر/عشرة agrees with the counted noun.
- Masculine nouns take forms such as ثلاثة عشر; feminine nouns take forms such as ثلاث عشرة.
- The entire compound is case-invariant and built on fatḥ.
- The counted noun is always an indefinite singular accusative specification.
- Eighteen before a feminine noun is ثماني عشرة, and two-digit place value is never reversed by Arabic text direction.
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Start learning Arabic →Related Topics
- Numbers 11 and 12A2 — Form eleven and twelve with gender agreement, a singular accusative counted noun, and the visible nominative–oblique contrast of twelve.
- The Decades 20–90A2 — Decline the decades like sound masculine plurals, keep them gender-invariant, and use a singular accusative counted noun.
- Numbers 0–10 in IsolationA1 — Read, pronounce, and distinguish the citation and gender-paired forms of Arabic zero through ten before building counted-noun phrases.