An Arabic attributive adjective agrees with its noun in case as well as gender, number, and definiteness. A nominative noun takes a nominative adjective, an accusative noun an accusative adjective, and a genitive noun a genitive adjective. The two words do not always display the same vowel, however: agreement means the same case category, not necessarily an identical-looking ending.
This page uses the case system of (formal) contemporary Modern Standard Arabic. In ordinary formal speech, sentence-final short endings are often suppressed by pause. Because this page is specifically teaching case, its case drills and several sentence examples deliberately pronounce the relevant final endings; that careful (formal) reading style makes the contrast audible. Review the nominal declension behind the patterns on Triptote Nouns and Diptote Nouns.
Triptote adjectives: the regular three-case pattern
Most ordinary singular adjectives are triptotes. When indefinite, they use ـٌ -un for nominative, ـًـا -an for accusative, and ـٍ -in for genitive. The noun and adjective each carry their own ending.
| Case | Indefinite phrase | Typical role |
|---|---|---|
| nominative | موظفٌ جديدٌ | subject or predicate |
| accusative | موظفًا جديدًا | direct object |
| genitive | موظفٍ جديدٍ | after a preposition or as an iḍāfa dependent |
موظف جديد
muwaẓẓafun jadīdun
a new employee — nominative
موظفا جديدا
muwaẓẓafan jadīdan
a new employee — accusative
موظف جديد
muwaẓẓafin jadīdin
a new employee — genitive
Definiteness removes tanwīn but not the case contrast: الموظفُ الجديدُ، الموظفَ الجديدَ، الموظفِ الجديدِ. Both members take الـ, and both take the relevant short case vowel.
وصل الموظف الجديد إلى المكتب.
waṣala l-muwaẓẓafu l-jadīdu ʾilā l-maktab.
The new employee arrived at the office. The noun phrase is nominative.
قابلت الموظف الجديد عند المدخل.
qābaltu l-muwaẓẓafa l-jadīda ʿinda l-madkhal.
I met the new employee at the entrance. The noun phrase is accusative.
تحدثت مع الموظف الجديد بعد الاجتماع.
taḥaddathtu maʿa l-muwaẓẓafi l-jadīdi baʿda l-ijtimāʿ.
I spoke with the new employee after the meeting. The noun phrase is genitive after مع.
A four-way nominative agreement set
Case agreement sits on top of gender and number agreement. The following subjects are all nominative, but each adjective also chooses the form required by its human head noun.
حضر الباحث الجديد الندوة.
ḥaḍara l-bāḥithu l-jadīdu n-nadwa(h).
The new male researcher attended the seminar.
حضرت الباحثة الجديدة الندوة.
ḥaḍarati l-bāḥithatu l-jadīdatu n-nadwa(h).
The new female researcher attended the seminar.
حضر الباحثون الجدد الندوة.
ḥaḍara l-bāḥithūna l-jududu n-nadwa(h).
The new male researchers attended the seminar.
حضرت الباحثات الجديدات الندوة.
ḥaḍarati l-bāḥithātu l-jadīdātu n-nadwa(h).
The new female researchers attended the seminar.
Because the verb comes before the overt plural subject here, neutral formal MSA uses a singular verb: حضر الباحثون and حضرت الباحثات. That verb–subject asymmetry is separate from adjective agreement; the postnominal adjectives still show full human plural agreement.
Duals and sound plurals
Case can be visible in long endings rather than short vowels. Dual nouns and adjectives use ـانِ in the nominative but ـينِ in the accusative and genitive. Sound masculine plurals likewise contrast ـونَ with ـينَ.
| Type | Nominative | Accusative / genitive |
|---|---|---|
| masculine dual | الطالبان المجتهدان | الطالبين المجتهدين |
| sound masculine plural | المهندسون المصريون | المهندسين المصريين |
| sound feminine plural | باحثاتٌ مجتهداتٌ | باحثاتٍ مجتهداتٍ |
The sound feminine plural is especially instructive: its accusative and genitive ending is ـاتٍ, with kasra. A feminine singular adjective modifying a sound feminine nonhuman plural may nevertheless show fatḥa in the accusative because the two words belong to different declension classes.
كرمت الجامعة باحثات مجتهدات.
karramati l-jāmiʿatu bāḥithātin mujtahidātin.
The university honored diligent female researchers. Both plural words are accusative.
ناقشنا اقتراحات مهمة في الجلسة.
nāqashnā qtirāḥātin muhimmatan fī l-jalsa(h).
We discussed important proposals in the session. Both words are accusative despite their different vowels.
In اقتراحاتٍ مهمةً, اقتراحاتٍ is a sound feminine plural form with non-rational, nonhuman reference, whereas مهمةً is a feminine singular triptote adjective. Kasra and fatḥa therefore express the same accusative case. This is why matching case cannot mean “copy the last vowel.”
Diptote adjectives
Some adjective patterns are diptote, including the common color-and-defect pattern أفعل, as in أحمر “red.” An indefinite diptote has no tanwīn and normally uses fatḥa for both accusative and genitive.
معطف أحمر
miʿṭafun ʾaḥmaru
a red coat — nominative; the diptote adjective ends in -u without tanwīn
اشتريت معطفا أحمر.
ʾishtaraytu miʿṭafan ʾaḥmara.
I bought a red coat. Both words are accusative.
مررت بمعطف أحمر.
marartu bi-miʿṭafin ʾaḥmara.
I passed by a red coat. Both words are genitive, though their endings differ.
Once a diptote adjective is definite with الـ, it shows kasra in the genitive like an ordinary definite triptote.
مررت بالمعطف الأحمر.
marartu bi-l-miʿṭafi l-ʾaḥmari.
I passed by the red coat. The definite adjective has genitive -i.
Phrase, predicate, and iḍāfa scope
An adjective inside a definite phrase matches both definiteness and case. A predicate matches the subject in gender and number but remains indefinite; in a simple nominal sentence, both subject and predicate are normally nominative.
الباحثون المجتهدون
al-bāḥithūna l-mujtahidūna
the diligent researchers — one definite noun phrase
الباحثون مجتهدون.
al-bāḥithūna mujtahidūna.
The researchers are diligent — a subject plus an indefinite predicate
Case can identify adjective scope in an iḍāfa. In ملخص الدراسة, the head ملخص is accusative after قرأت, while الدراسة is genitive as the dependent. The adjective's gender and case show which noun it modifies.
قرأت ملخص الدراسة الجديد قبل الدرس.
qaraʾtu mulakhkhaṣa d-dirāsati l-jadīda qabla d-dars.
I read the new summary of the study before class.
قرأت ملخص الدراسة الجديدة قبل الدرس.
qaraʾtu mulakhkhaṣa d-dirāsati l-jadīdati qabla d-dars.
I read the summary of the new study before class.
Common Mistakes
Keeping nominative long endings on an object
❌ قابلت المترجمون الماهرون في المطار.
Incorrect — the direct object requires accusative -ين on both sound masculine plural words.
✅ قابلت المترجمين الماهرين في المطار.
qābaltu l-mutarjimīna l-māhirīna fī l-maṭār.
I met the skilled translators at the airport.
Putting the adjective before the noun
❌ جديدا اشتريت حاسوبا.
Incorrect for “I bought a new computer” — the attributive adjective follows its noun.
✅ اشتريت حاسوبا جديدا للعمل.
ʾishtaraytu ḥāsūban jadīdan li-l-ʿamal.
I bought a new computer for work.
Omitting definiteness agreement
❌ راجعت العقد جديد قبل التوقيع.
Incorrect — the intended attributive adjective must match the definite object.
✅ راجعت العقد الجديد قبل التوقيع.
rājaʿtu l-ʿaqda l-jadīda qabla t-tawqīʿ.
I reviewed the new contract before signing.
Using plural agreement for nonhuman nouns
❌ قرأت الكتب المفيدين في العطلة.
Incorrect — nonhuman كتب requires a feminine singular adjective.
✅ قرأت الكتب المفيدة في العطلة.
qaraʾtu l-kutuba l-mufīdata fī l-ʿuṭla(h).
I read the useful books during the vacation.
Guessing gender from English
❌ فتحت النافذة الصغير للهواء.
Incorrect — نافذة is grammatically feminine, so its adjective must be feminine too.
✅ فتحت النافذة الصغيرة للهواء.
fataḥtu n-nāfidhata ṣ-ṣaghīrata li-l-hawāʾ.
I opened the small window for some air.
Key Takeaways
- An attributive adjective carries the same case category as its noun.
- Case agreement does not guarantee identical surface vowels across different declension classes.
- Dual and sound masculine plural endings make the nominative versus accusative/genitive contrast especially visible.
- Indefinite diptotes use fatḥa in the genitive; definiteness restores genitive kasra.
- Case, gender, number, and definiteness jointly identify phrase structure and adjective scope.
Now practice Arabic
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Arabic →Related Topics
- Definite versus Indefinite AdjectivesA2 — Use definiteness agreement to distinguish an adjective inside a noun phrase from an adjective serving as the predicate of a sentence.
- Adjectives with Non-Human PluralsA2 — Apply feminine singular adjective agreement to nonhuman plural nouns while preserving definiteness, case, and phrase structure.
- Adjective Agreement: Gender, Number, Case, and DefinitenessA1 — Build Arabic noun phrases by matching adjectives in gender, number, case, and definiteness, including the nonhuman-plural pattern.