Nominative case

The nominative (al-marfū‘ ٱلْمَرْفُوعُ) is used in several situations:

• For the subject of a verbal sentence.
• For the subject and predicate of a non-verbal (equational) sentence, with some notable exceptions.
• For certain adverbs.
• For the citation form of words.

For singular nouns and broken plurals, it is marked as a usually unwritten ضَمَّة ḍammah (-u) for the definite or ḍammah + nunation (-un) for the indefinite. The dual and regular masculine plural are formed by adding ـَانِ -an(i) and ـُونَ -ūn(a) respectively (just ـَا -ā and ـُو -ū in the construct state). The regular feminine plural is formed by adding ـَاتُ -āt(u) in the definite and ـَاتٌ -āt(un) in the indefinite (same spelling).

Accusative case

The accusative (al-manṣūb ٱلْمَنْصُوب) has several uses:

• The subject of an equational (non-verbal) sentence, if it is initiated with إن inna, or one of its sisters. The particles are subordinating conjunctions which require that the subject of the subordinate (complement) clause be in the accusative case.
• The predicate of كَانَ / يَكُونُ kāna/yakūnu "be" and its sisters (there are 13 of these verbs).^[1] Hence, ٱلْبِنْتُ جَمِيلَةٌ al-bintu jamīlatun 'the girl is beautiful' but ٱلْبِنْتُ كَانَتْ جَمِيلَةً al-bintu kānat jamīlatan 'the girl was beautiful' ("beautiful" is spelled the same way in both cases).
• Both the subject and the predicate of ظَنَ ẓanna and its sisters in an equational clause.
• As the complement of verbs of "seeming".
• The object of a transitive verb
• Most adverbs.
• Semi-prepositions.
• Internal object/cognate accusative structure
• The accusative of specification (al-tamyīz, ٱلتَّمْيِيزُ).
• The accusative of purpose (al-maf‘ūl li-ajlihi, ٱلْمَفْعُولُ لِأَجْلِهِ).
• The circumstantial accusative (al-ḥāl, ٱلْحَال).
• Objects of (kam, كَمْ) 'how much/how many'.
• Cardinal and ordinal numbers from 11, and 13-19
• Counted nouns of numbers 11–99
• Exclamation of astonishment. i.e.: mā ajmalahā!, !مَا أَجْمَلَهَا 'Oh, how beautiful she is!'
• Vocative first term of construct. يَا عبدَ اللهِ yā ‘abd-a-llah! "Oh, Abdallah!"
• Nouns following exceptive particles in non-negative sentences.
• The noun following the absolute, or categorical, negation لَا lā "No".

For singular nouns and broken plurals, it is marked as a usually unwritten فَتْحَة fatḥah (-a) for the definite or fatḥah + nunation (-an) for the indefinite. For the indefinite accusative, the fatḥah + nunation is added to an ا alif, e.g. ـًا, which is added to the ending of all nouns not ending with a alif followed by hamzah or a tā’ marbūṭah. This is the only case (when alif is written), which affects the unvocalised written Arabic (e.g. بَيْتاً bayt-an). The dual and regular masculine plural are formed by adding ـَيْنِ -ayn(i) and ـِينَ -īn(a) respectively (spelled identically!) (ـَيْ -ay and ـِي -ī in the construct state, again, spelled identically). The regular feminine plural is formed by adding ـَاتِ -āt(i) in the definite and -āt(in) in the indefinite (spelled identically). Some forms of indefinite accusative are mandatory even for spoken and pausal forms of Arabic, sometimes -an is changed to a simple -a in pausa or spoken Arabic.

Diptotes never take an alif ending in the written Arabic and are never pronounced with the ending -an.

Genitive case

The genitive case (al-majrūr, ٱلْمَجْرُورُ)

• Objects of prepositions.
• The second, third, fourth, etc. term of an iḍāfah (إِضَافَةٌ genitive construction).
• The object of a locative adverb.
• Elative (comparative/superlative) adjectives behave similarly: أَطْوَلُ وَلَدٍ aṭwalu waladin 'tallest boy'.

For singular nouns and broken plurals, it is marked as a usually unwritten كَسْرَة kasrah (-i) for the definite or kasrah + nunation (-in) for the indefinite. The dual and regular masculine plural are formed by adding ـَيْنِ -ayn(i) and ـِيْنَ -īn(a) respectively (spelled identically) (ـَيْ -ay and ـِي -ī in the construct state, again, spelled identically). The regular feminine plural is formed by adding ـَاتِ -āt(i) in the definite and ـَاتٍ -āt(in) in the indefinite (spelled identically in Arabic).

Note: diptotic nouns receive a fatḥah (-a) in the genitive and are never nunated.

Note: there is no dative case. Instead, the preposition لـِ li- is used.

Fully declined nouns (triptotes)

For fully declined nouns, known as "triptote" (‏مُنْصَرِفٌ‎ munṣarif), that is, having three separate case endings, the suffixes are -u, -a, -i for nominative, accusative, and genitive case respectively, with the addition of a final /n/ (nunation, or tanwīn) to produce -un, -an, and -in when the word is indefinite.

This system applies to most singular nouns in Arabic. It also applies to feminine nouns ending in ة -a/-at (tā’ marbūṭah) and ء hamzah, but for these, ا alif is not written in the accusative case. It also applies to many "broken plurals". When words end in -a/-at (tā’ marbūṭah) the t is pronounced when the case ending is added; thus رِسَالَة ("message") is pronounced risāla in pausal form, but in Classical Arabic it becomes رِسَالَةٌ risālatun, رِسَالَةً risālatan, and رِسَالَةٍ risālatin when case endings are added (all usually spelled رسالة when written without the vowel points).

The final /n/ is dropped when the noun is preceded by the definite article al-). The /n/ is also dropped when the noun is used in iḍāfah (construct state), that is, when it is followed by a genitive. Thus:

Nominative (مَرْفُوعٌ marfū‘ ; literally, "raised"):

baytun بَيْتٌ : a house

al-baytu ٱلْبَيْتُ : the house

baytu r-rajuli بَيْتُ ٱلرَّجُلِ : the house of the man.

Accusative (مَنْصُوبٌ manṣūb); literally, 'erected'):

baytan بَيْتًا : a house

al-bayta ٱلْبَيْتَ : the house

bayta r-rajuli بَيْتَ ٱلرَّجُلِ : the house of the man.

Genitive (مَجْرُورٌ majrūr; literally, 'dragged'):

baytin بَيْتٍ : a house

al-bayti ٱلبَيْتِ : the house

bayti r-rajuli بَيْتِ ٱلرَّجُلِ : the house of the man.

The final /n/ is also dropped in classical poetry at the end of a couplet, and the vowel of the ending is pronounced long.

Diptotes

A few singular nouns (including many proper names and names of places), and certain types of "broken plural", are known as diptotes (ٱلْمَمْنُوعُ مِنْ ٱلصَّرْفِ al-mamnū‘ min aṣ-ṣarf, literally 'forbidden from inflecting') meaning that they only have two case endings.

When the noun is indefinite, the endings are -u for the nominative and -a for the genitive and accusative with no nunation. The genitive reverts to the normal -i when the diptotic noun becomes definite (preceded by al- or is in the construct state)).

Diptotes never take an alif in the accusative case in written Arabic.

Sound masculine plurals

In the case of sound masculine plurals (جَمْعُ ٱلْمُذَكَّرُ ٱلسَّالِمُ - jam‘ al-mudhakkar as-sālim), mostly denoting male human beings, the suffixes are respectively ـُونَ -ūna and ـِينَ -īna. These stay the same whether ال al- precedes or not. The final -a is usually dropped in speech. In less formal Arabic only -īna is used for all cases and the final -a is dropped in pausa and in less formal Arabic.

The ن -na is dropped when the noun is in iḍāfah (construct state). Thus:

Nominative:

وَالِدُونَ wālidūna: parents (more than two)

ٱلْوَالِدُونَ al-wālidūna: the parents

وَالِدُو ٱلرِّجَالِ wālidū r-rijāli: the parents of the men

Accusative and genitive:

وَالِدِينَ wālidīna: parents

ٱلْوَالِدِينَ al-wālidīna: the parents

وَالِدِي ٱلرِّجَالِ wālidī r-rijāli: the parents of the men

Note: ending ـِينَ -īna is spelled identically to ـَيْنِ -ayni (see above).

Sound feminine plurals

In the case of sound feminine plurals (جَمْعُ ٱلْمُؤَنَّثُ ٱلسَّالِمُ jam‘ al-mu’annath as-sālim), the suffixes are respectively ـَاتٌ, ـَاتُ -ātu(n), ـَاتٍ, ـَاتِ -āti(n) and ـَاتٍ, ـَاتِ -āti(n) (identical spelling). The n is only there when the noun is indefinite (not preceded by al-). Again the final vowel is dropped in speech and pausa, leaving only ـَات -āt, making all cases pronounced identically.

The final "n" is dropped when the noun is in iḍāfah (construct state).

Nominative:

مُدَرِّسَاتٌ mudarrisātun: (female) teachers

ٱلْمُدَرِّسَاتُ al-mudarrisātu: the teachers

مُدَرِّسَاتُ ٱلْأَوْلَادِ mudarrisātu l-awlādi: the teachers of the children

Accusative and genitive:

مُدَرِّسَاتٍ mudarrisātin: (female) teachers

ٱلْمُدَرِّسَاتِ al-mudarrisāti: the teachers

مُدَرِّسَاتِ ٱلْأَوْلَادِ mudarrisāti l-awlādi: the teachers of the children

Other declensional paradigms

The Dual - These nouns denote two of something. They decline very similarly to the sound masculine plurals because they are not marked for definiteness and look the same in both the accusative and genitive cases. For the nominative, the marking is -āni and for the accusative/genitive, -ayni. An example is "parents," which is wālidāni and wālidayni respectively.

ٱسْمُ ٱلْمَنْقُوصِ ism al-manqūṣ (deficient nouns ending with yā’ ) - These nouns behave differently due to the instability of the final vowel. When indefinite, these nouns take a final -in in the nominative/genitive, and -iyan in the accusative. When definite, they take a long -ī in the nominative/genitive, and -iya in the accusative. These nouns were reckoned by the grammarians to have originally taken the triptotic endings, but through morpho-phonotactic processes, the latter resulted. An example is "judge," which is qāḍin, qāḍiyan, versus al-qāḍī, and al-qāḍiya respectively. Also, a noun can be both ism al-manqūṣ and diptotal: for example, layālin 'nights', is a broken plural with a final unstable vowel. With case endings this noun becomes layālin, layāliya, and al-layālī, al-layāliya.

ٱسْمُ ٱلْمَقْصُورِ ism al-maqṣūr (deficient nouns ending with alif or alif maqṣūrah) - These nouns, like their close relative ism al-manqūṣ, also behave differently due to the instability of a final vowel. These nouns are marked only for definiteness, as morpho-phonotactic processes have resulted in the complete loss of the case distinctions. When indefinite, they take -an, which rests on an alif maqṣūrah or occasionally alif. When definite, they are not marked, and they simply retain their long alif or alif maqṣūrah. An example is "hospital," which is mustashfan and al-mustashfā respectively. If a noun is both ism al-maqṣūr and diptotic, then it is completely invariable for case.

Invariable nouns - Invariable nouns are usually those foreign names that end in alif or nouns that end in an additional alif or alif maqṣūrah (when that alif or alif maqṣūrah is not part of the root). Also, nouns that are both ism al-maqṣūr and diptotic fall into this category. Additionally, there are rare invariable nouns which have other endings, like any name ending with "-ayhi," like Sībawayhi (colloquially pronounced, for example, in Egypt: [sebæˈweː]. An example of a common invariable noun is fuṣḥá (al-fuṣḥá), meaning 'the most eloquent [Arabic]'. Another example is dunyā (al-dunyā) 'world'.

Verbal sentences

In a verbal sentence (ٱلْجُمْلَةُ ٱلْفِعْلِيَّةُ al-jumlah al-fi‘līyah), there is verb–subject–object word order. This is the preferred word order of Classical Arabic.

In a verbal sentence, the subject takes nominative case and the object takes accusative case. Such a sentence ("This writer wrote the written") would be formed as follows (read from right to left):

Nominal sentences

In a nominal sentence (ٱلْجُمْلَةُ ٱلْاِسْمِيَّةُ al-jumlah al-ismīyah), there is subject–verb–object word order.