Case in Nominal Sentences

The basic Arabic nominal sentence has no present-tense word corresponding to English “is.” It joins a subject/topic (مبتدأ) to a predicate/comment (خبر), and both are normally nominative. That simple pattern becomes much more revealing when the predicate comes first, or when إنّ and كان enter: إنّ makes its subject accusative while leaving its predicate nominative, whereas كان keeps its subject nominative and makes its predicate accusative.

These are not arbitrary lists of endings. The case pattern tells you which element occupies which structural role, even when word order changes, ordinary spelling omits the endings, or a phrase cannot display nominative case overtly.

(formal) The nominal-sentence structures themselves are central across Arabic, but the overt nominative and accusative endings taught here belong to inflected contemporary MSA. Regional colloquial varieties express many of the same relations without this full case paradigm.

The case and iʿrāb overview introduces the general system; this page follows case specifically through nominal predication.

The baseline: subject and predicate are nominative

In the unmarked pattern, the nominal subject is often definite and the predicate often indefinite. Both take nominative case in connected, fully inflected reading:

In الجوُّ معتدلٌ, الجوّ is the nominative subject and معتدل the nominative predicate. In نتائجُ الدراسةِ, only the iḍāfa head نتائج is the nominative subject; الدراسةِ is genitive because it is the possessor. One noun phrase can therefore contain more than one case relation.

Predicates are not always single nouns or adjectives

A predicate can be a prepositional phrase, an adverbial phrase, or an entire clause. Such predicates do not show an ordinary nominative ending on the phrase as a whole. Traditional analysis says the expression is in the nominative position (في محل رفع خبر).

The preposition في governs genitive القاعةِ, but the full phrase في القاعة الكبرى functions locally as the nominative predicate. There is no contradiction: “genitive” describes the noun inside the phrase, while “in the nominative position” describes the phrase’s role in the larger sentence.

Here the verbal clause ينتظرون إعلان النتائج is the predicate in the nominative position. Its internal grammar still includes an indicative verb and accusative object.

Fronted predicates: position does not make a subject

Arabic commonly places a prepositional or adverbial predicate before an indefinite subject. This is natural formal MSA, not a poetic inversion. In في المكتب ضيفٌ, في المكتب is the fronted predicate and ضيفٌ the delayed nominative subject.

In the second example, adverbial أمامَ is the fronted predicate, while سياراتُ إسعافٍ is the delayed nominative subject. The first term of that iḍāfa, سيارات, carries nominative case; the second, إسعاف, is genitive. An English-first assumption that “the first noun phrase is the subject” cannot parse these sentences.

Fronting can also support contrastive focus, though ordinary prose strongly prefers a subject-first order when both orders would be grammatical. Register and information structure matter: not every grammatically possible order is equally neutral.

إنّ: accusative subject, nominative predicate

إنّ is a complementizer and emphatic particle often translated “indeed,” “certainly,” or simply “that,” depending on context. It governs its nominal subject in the accusative; its predicate remains nominative. Traditional labels are اسم إنّ and خبر إنّ.

The second sentence uses أنّ, the embedded counterpart of إنّ. It applies the same case pattern: accusative النتائجَ, nominative موثوقةٌ.

If the predicate is a phrase, its local status remains nominative even though an internal noun is genitive:

Here الاجتماعَ is the accusative subject of إنّ. The phrase في القاعة الكبرى is its predicate in the nominative position, while القاعةِ is genitive inside that phrase.

كان: nominative subject, accusative predicate

كان and its sisters introduce tense, aspect, negation, or change of state into a nominal predication. With basic past كان, the former nominal subject remains nominative as اسم كان, and the predicate becomes accusative as خبر كان.

The linking kasra in كانتِ المديرةُ is phonetic: it prevents two consonants from colliding before the definite article. It is not genitive case on the verb.

A prepositional predicate after كان is still analyzed as being in the accusative position, though the preposition governs genitive internally:

Because a phrase has no single case vowel marking its external role, this distinction is local rather than visible.

The three-way contrast

The most efficient way to internalize the system is to keep one proposition and change only the governor:

This contrast also explains why calling إنّ or كان a translation of English “is/was” is insufficient. Their grammatical effect on the two nominal constituents is different and predictable.

Connected endings, natural pause, and unvocalized print

This page pronounces endings in connected contrasts because the endings are the teaching point. In ordinary formal delivery, a speaker can pause after the final predicate and suppress its short vowel:

The predicate نهائيّ is still nominative even though the pausal form does not pronounce -un. Do not add an ending merely to prove an analysis, and do not infer absence of case from an ordinary pause.

For an unvocalized parsing task, take إن المدير في المكتب. The particle identifies المدير as its accusative subject even though print does not show -a. The prepositional phrase is the predicate in the nominative position, and المكتب is genitive after في.

Key Takeaways

The basic nominal sentence assigns nominative to both subject and predicate. إنّ changes its subject to accusative while the predicate stays nominative; كان keeps its subject nominative and changes the predicate to accusative. A phrase can hold one of these roles locally while a preposition governs genitive inside it.

Common Mistakes

Mistake 1: making the basic predicate accusative.

Mistake 2: leaving the subject nominative after إنّ.

Mistake 3: making the subject accusative after كان.

Mistake 4: treating the first phrase as the subject.

Mistake 5: calling every fatḥa an accusative noun ending.

The ending -a on يكونَ marks verb mood; طويلًا carries noun/adjective case. Arabic uses related traditional labels for both, but their governors and paradigms are distinct.

The essential map is compact: ordinary nominal sentence nominative + nominative; إنّ: accusative subject + nominative predicate; كان: nominative subject + accusative predicate. Phrases can carry those roles locally, internal prepositions still govern genitive, and pause can silence an ending without changing the syntax.