Cases
Three small final vowels carry a lot of grammar — when they're written, which is less often than you might expect.
Arabic has a case system. Nouns and adjectives change form depending on whether they are the subject, the object, or the possessor of something. The change is usually just a single short vowel at the very end of the word. In the formal Modern Standard Arabic of newsreaders and Quranic recitation, those vowels are pronounced and grammatically required. In ordinary printed text they are typically not written at all, and in spoken dialect they have effectively disappeared. So Arabic looks like it has a complicated case system, and on paper it does — but in practice English speakers see and hear it less than they expect.
The three cases
Modern Standard Arabic has three cases:
- Nominative — for the subject and for things equated with the subject (predicate nouns). Marked with a final -u when definite, -un when indefinite.
- Accusative — for the direct object, for adverbial complements, and for the predicate after certain verbs and particles. Marked -a definite, -an indefinite.
- Genitive — for the noun after a preposition and for the second noun in idafa (the possessor). Marked -i definite, -in indefinite.
The full set of indefinite endings (-un, -an, -in) is called tanwiin — the doubling of the case vowel into a final n sound.
The same noun in the definite (with al-):
A worked sentence
Where the cases actually appear
Three layers, in decreasing visibility:
- Fully vocalized texts — the Quran, school textbooks, poetry, dictionaries — show every case ending. Read aloud they are pronounced.
- Newscasts and formal speech sometimes pronounce the case endings, but at the end of a phrase (the pause) they are usually dropped. So al-kitaabu becomes al-kitaab at a stop.
- Ordinary newspapers, novels, and signs omit the case vowels in writing, and reading them aloud does the same. Spoken dialect drops them altogether — Egyptian, Levantine, Maghrebi Arabic do not use case at all.
The result: most Arabic you read does not show the case ending. You still need to know the system, because it tells you what role each noun is playing — and because, even when not pronounced, it surfaces in the spelling of certain words.
The five nouns
A small set of nouns, called الأَسْماء الخَمْسَة (al-asmaa' al-khamsa, the five nouns), use long vowels for their case markers when followed by a possessor:
The five nouns are: ab (father), akh (brother), Ham (father-in-law), fuu (mouth), dhuu (possessor of). They show up in fixed expressions and proper names — Abuu Bakr, Abii Taalib — even in otherwise unvocalized text.
Diptotes vs. triptotes
Most nouns are triptotes — they take all three case endings and accept tanwiin. A minority are diptotes — they take only two endings (-u for nominative, -a for both accusative and genitive) and never take tanwiin. Diptotes include many proper names (AHmad, ʿUmar), most words on the pattern afʿal (including comparatives and color words: akbar, aHmar), and certain plural patterns. The practical effect is small in everyday writing but becomes visible in fully vocalized formal text.
Why English speakers find this hard — and easy
The good news first. English does have a vestigial case system — I/me, he/him, who/whom — so the concept is not totally alien. The Arabic system is far more regular than, say, German or Russian: three cases, predictable endings, almost always just one short vowel. There are no irregular paradigms.
The hard part is the inconsistency of exposure. The case is sometimes written, often not, sometimes pronounced, often not. Beginners tend to drift between trying to memorise endings and ignoring them. The honest advice: learn the system early, use it in formal writing and in any sentence you read aloud carefully, and don't worry about it in casual conversation. Knowing the case system pays back enormously when you start reading classical or formal texts.
What it's called in the Arabic tradition
The discipline of case and final-ending changes is إعْراب (iʿraab). Nominative is رَفْع (rafʿ), accusative is نَصْب (naSb), genitive is جَرّ (jarr). The tanwiin doubling is تَنْوين. Diptote and triptote are مَمْنوع مِن الصَّرْف (mamnuuʿ min aS-Sarf, "blocked from full inflection") and مُنْصَرِف (munSarif) respectively.