The Arabic genitive, المجرور, marks a noun phrase governed by a preposition or placed as the second term of an iḍāfa. On a regular singular triptote, a definite genitive has -i and an indefinite genitive has -in: في المكتبِ “in the office” and في مكتبٍ “in an office.” English normally uses a preposition or an of phrase; Arabic also makes the governed relation part of the noun's inflection.
Genitive case does not always sound like i. Duals and sound masculine plurals use the oblique endings ـينِ / ـينَ, shared with the accusative. An indefinite diptote normally realizes genitive with fatḥa. A noun ending in ى may have an estimated genitive, and an indeclinable pronoun or demonstrative can occupy a local genitive position. At sentence-final pause, the audible short -i/-in is normally silenced. The syntactic relation remains genitive in every case.
The overview What Iʿrāb Does explains how syntactic case survives hidden endings; this page applies that principle to prepositions and iḍāfa.
Prepositions govern genitive complements
A preposition is the governor of the noun phrase that immediately complements it. Common prepositions include في “in,” إلى “to,” من “from,” عن “about/from,” على “on,” بـ “with/by,” لـ “for/to,” and كـ “like/as.” The governed phrase is genitive.
ذهبت إلى المكتبة بعد العمل.
dhahabtu ʾilā l-maktabati baʿda l-ʿamal.
I went to the library after work.
Preposition إلى governs definite المكتبةِ, so its regular singular marker is -i. Later بعدَ is an accusative adverbial noun that begins an iḍāfa; its complement العملِ is genitive, though final pause silences the short vowel.
An indefinite complement carries -in when fully connected.
تحدثت مع موظف جديد في الممر.
taḥaddathtu maʿa muwaẓẓafin jadīdin fī l-mamarr.
I spoke with a new employee in the corridor.
مع governs موظفٍ, and adjective جديدٍ agrees in genitive case and indefiniteness. Final الممر is also genitive after في, but its short -i is silenced at pause.
Prefixed بـ، لـ، كـ attach orthographically to what follows. They still govern genitive.
أرسلنا النسخة للمدير بالبريد الإلكتروني.
ʾarsalnā n-nuskhata li-l-mudīri bi-l-barīdi l-ʾilikturūniyy.
We sent the copy to the director by email.
Attached لـ governs المديرِ, and بـ governs البريدِ. Adjective الإلكتروني follows البريد in definiteness and genitive case; sentence-final pause hides its short -i.
The second term of iḍāfa
An iḍāfa links two nouns: “X of Y,” “Y's X,” or a conventional noun–noun relation. The first term is the construct head; the second term is genitive because the construct relation governs it. The first term gets its own case from the larger sentence.
فتح حارس المبنى باب المكتب في السابعة.
fataḥa ḥārisu l-mabnā bāba l-maktabi fī s-sābiʿa(h).
The building guard opened the office door at seven.
Subject head حارسُ is nominative, while its second term المبنى is genitive with an estimated ending on final ى. Direct-object head بابَ is accusative, while second term المكتبِ is visibly genitive. The iḍāfa controls only its second term; the clause controls its head.
If the second term is indefinite, it normally takes genitive -in, and the entire construct is indefinite.
هذا باب مكتب صغير في الطابق الثاني.
hādhā bābu maktabin ṣaghīrin fī ṭ-ṭābiqi th-thānī.
This is the door of a small office on the second floor.
Predicate head بابُ is nominative but has no tanwīn because it begins an iḍāfa. مكتبٍ is its indefinite genitive complement. Adjective صغيرٍ modifies مكتب, so it too is indefinite genitive. The final adjective الثاني modifies definite الطابق and is genitive, with pause suppressing its final short vowel.
Iḍāfa can form longer chains. Every nonfinal noun is a construct head without الـ or tanwīn, while each following relation places the next noun in genitive.
ناقشنا خطة قسم الموارد البشرية صباحا.
nāqashnā khuṭṭata qismi l-mawāridi l-bashariyyati ṣabāḥā.
We discussed the human resources department's plan in the morning.
Accusative خطةَ is the object and first construct head. قسمِ is genitive after it and simultaneously heads قسم الموارد. المواردِ is genitive and is modified by genitive البشريةِ. A chain should be parsed from the relationships, not translated one word at a time from left to right.
Definite -i, indefinite -in, and missing tanwīn
The genitive ending of a regular singular triptote depends on definiteness. الـ produces -i without tanwīn; a genuinely indefinite noun produces -in. A proper name or construct may be definite without الـ, and a construct head never takes tanwīn.
استمعت إلى شرح واضح ثم إلى شرح المدرب.
ʾistamaʿtu ʾilā sharḥin wāḍiḥin thumma ʾilā sharḥi l-mudarrib.
I listened to a clear explanation and then to the trainer's explanation.
First شرحٍ واضحٍ is indefinite genitive with -in. Second شرحِ is genitive too, but it has no tanwīn because it begins the definite construct شرح المدرب. Final المدرب remains genitive although it is read pausally.
A compact three-case set keeps the genitive in perspective:
وصل موظف جديد، وقابلت موظفا جديدا، وتحدثت مع موظف جديد.
waṣala muwaẓẓafun jadīdun, wa-qābaltu muwaẓẓafan jadīdan, wa-taḥaddathtu maʿa muwaẓẓafin jadīd.
A new employee arrived; I met a new employee; and I spoke with a new employee.
The governors are respectively the active verb's subject relation, the transitive verb's object relation, and preposition مع. Final adjective جديد is still genitive in the third clause even though pause removes audible -in.
Duals and sound masculine plurals
The dual and sound masculine plural merge accusative and genitive into one oblique form: dual -ayni and plural -īna. Syntax distinguishes the two cases.
تحدثت مع المهندسين عن المشروعين الجديدين.
taḥaddathtu maʿa l-muhandisīna ʿani l-mashrūʿayni l-jadīdayn.
I spoke with the engineers about the two new projects.
مع governs genitive plural المهندسين. عن governs genitive dual المشروعين, and adjective الجديدين agrees. The same written forms could be accusative objects elsewhere, so the prepositions and roles determine the analysis.
Diptote genitive: fatḥa can mean genitive
An indefinite diptote normally has no tanwīn and realizes genitive with fatḥa. This is a morphological exception, not a change in syntactic role.
صلينا في مساجد قديمة خلال الرحلة.
ṣallaynā fī masājida qadīmatin khilāla r-riḥla(h).
We prayed in old mosques during the trip.
Preposition في makes مساجدَ genitive, but indefinite diptote مساجد realizes it with -a and no tanwīn. Its adjective قديمةٍ is a regular triptote and therefore shows ordinary genitive -in.
When the same diptote becomes definite with الـ or is the first term of an iḍāfa, ordinary kasra returns.
زرنا ثلاثة من المساجد القديمة في المدينة.
zurnā thalāthatan mina l-masājidi l-qadīmati fī l-madīna(h).
We visited three of the old mosques in the city.
After من, definite المساجدِ is genitive with kasra, and adjective القديمةِ agrees. The diptote pattern is conditional, not an inherent ban on kasra in every environment.
Estimated and local genitive
A maqṣūr noun ending in ى cannot display a short genitive vowel; its case is estimated.
سلمت الملف إلى الفتى عند الباب.
sallamtu l-malaffa ʾilā l-fatā ʿinda l-bāb.
I handed the file to the young man at the door.
إلى governs الفتى, so it is genitive with an estimated ending. Attached pronouns and indeclinable forms instead occupy local genitive positions: in معه “with him,” preposition مع governs the attached pronoun locally, but no independent -i can be added.
ذهبت معه إلى المستشفى.
dhahabtu maʿahu ʾilā l-mustashfā.
I went with him to the hospital.
Attached ـه is locally genitive after مع, while المستشفى has estimated genitive after إلى. Neither relation is audibly marked by -i.
Pause and unvocalized writing
Ordinary print writes المكتب for nominative, accusative, and genitive forms. At sentence-final pause, في المكتبِ is normally pronounced fī l-maktab, without a final -i.
انتظرني في المكتب.
ʾintaẓirnī fī l-maktab.
Wait for me in the office.
The pause hides the genitive marker, but في remains the governor and المكتب remains its genitive complement. A careful connected continuation restores the ending: في المكتبِ صباحًا fī l-maktabi ṣabāḥā.
Common Mistakes
Leaving a sound masculine plural nominative after a preposition
❌ تحدثت مع المهندسون بعد العرض.
Incorrect — مع governs genitive, so the sound masculine plural must be المهندسين.
✅ تحدثت مع المهندسين بعد العرض.
taḥaddathtu maʿa l-muhandisīna baʿda l-ʿarḍ.
I spoke with the engineers after the presentation.
Failing to make the second term of iḍāfa genitive
❌ قرأت تقارير المعلمون.
Incorrect — the second term after تقارير is genitive, requiring المعلمين.
✅ قرأت تقارير المعلمين مساء.
qaraʾtu taqārīra l-muʿallimīna masāʾ.
I read the teachers' reports in the evening.
Inventing -i at a sentence-final pause
❌ انتظرني في المكتب.
ʾintaẓirnī fī l-maktabi
Incorrect as the neutral pausal reading — the noun is genitive, but final short -i is normally silenced.
✅ انتظرني في المكتب.
ʾintaẓirnī fī l-maktab.
Wait for me in the office.
Calling a diptote's genitive fatḥa accusative
❌ صلينا في مساجد قديمة.
ṣallaynā fī masājidin qadīmatin
Incorrect reading — في governs genitive, but indefinite diptote مساجد marks it with fatḥa and no tanwīn, not -in.
✅ صلينا في مساجد قديمة.
ṣallaynā fī masājida qadīma(h).
We prayed in old mosques.
Confusing verb mood with the following noun's case
❌ لم يصل المهندسين إلى الموقع.
Incorrect — لم governs jussive mood on يصل; it does not make the dual subject genitive or accusative.
✅ لم يصل المهندسان إلى الموقع.
lam yaṣili l-muhandisāni ʾilā l-mawqiʿ.
The two engineers did not arrive at the site.
Key Takeaways
- Prepositions govern their complements in the genitive; iḍāfa governs its second term in the genitive.
- Regular definite singulars show -i, and regular indefinite singulars show -in; constructs and other declension classes realize case differently.
- Dual and sound masculine plural genitives use forms shared with the accusative, so syntax distinguishes the cases.
- Indefinite diptotes can mark genitive with fatḥa; definite diptotes and diptotes in construct regain kasra.
- Estimated endings, local case, unvocalized writing, and pause can hide -i/-in without erasing genitive syntax.
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
- The AccusativeA1 — Use the accusative for direct objects, major adverbials, and predicates of كان while controlling -a, -an, and pausal forms.
- Case, Tanwīn, and DefinitenessA2 — Learn how nominative, accusative, and genitive case combine with nunation, the definite article, construct state, and pausal pronunciation.
- What Iʿrāb DoesA1 — Understand how nominative, accusative, and genitive case signal a noun phrase's role even when writing or pause hides the ending.