I'rab in Arabic: Why Word Endings Change, With Examples

I'rab in Arabic is the change in a word's final vowel that shows the job it is doing in the sentence. A noun ends in a damma (-u) when it is the doer or subject (raf'), a fatha (-a) when it is the object (nasb), and a kasra (-i) after a preposition or in a possessive pair (jarr).

That one idea explains why the same Arabic word can be spelt with three different endings on the same page of the mushaf. This guide to Arabic case endings (i'rab, often typed irab) covers what it is, why the endings change, the three cases with their vowels, how verbs fit in, which words never change, and ayat where a single vowel tells you who is doing what. It is written for beginners who can read Arabic with the vowel marks and want to start understanding what they read.

What is i'rab in Arabic?

I'rab in Arabic is the system of word endings that marks each word's grammatical role. The classic beginner's text of Arabic grammar, al-Ajurrumiyyah, defines it in one line: i'rab is the change in the endings of words because of the different governing factors that come before them, whether that change is heard or only implied. The word is also used for the exercise built on that system, where a student describes the role and ending of every word in a sentence. When you see a book called I'rab al-Qur'an, that is what it does, ayah by ayah.

Why do Arabic word endings change?

Arabic word endings change because Arabic marks roles with vowels where English marks them with word order. In English, "the man saw the boy" and "the boy saw the man" mean opposite things, and only the order tells you which. In Arabic the doer carries a damma and the object a fatha, so the words can move around and the meaning stays fixed. Something in the sentence always decides the ending. Grammarians call it the 'amil (governing factor): a verb that needs a doer and an object, a preposition that pulls the next noun into jarr, or a particle like inna. The name of Allah shows this clearly, taking all three endings in the Qur'an for three different reasons.

What are the three cases in Arabic?

The three cases in Arabic are raf', nasb and jarr, and a noun in each case is called marfu', mansub or majrur. Some books, al-Ajurrumiyyah among them, call jarr by its other name, khafd. Each case has a basic vowel, and when the noun is indefinite that vowel is doubled into tanween. In قُلْ هُوَ ٱللَّهُ أَحَدٌ (112:1), ahadun ends in -un, so it is marfu'. Read tanween as carefully as a single vowel, because it carries the same information.

Raf': the doer and the subject

Raf' is the case of the doer of a verb (the fa'il) and of the two halves of a nominal sentence, the subject (mubtada') and what is said about it (khabar). A noun that opens a nominal sentence as its subject is marfu'. In ٱلْحَمْدُ لِلَّهِ, al-hamdu (praise) opens the sentence as its subject, so it carries a damma.

Nasb: the object and more

Nasb is above all the case of the object, the thing a verb is done to (the maf'ul bihi). It also covers the noun straight after inna ("indeed") and the predicate of kana ("was"), along with several other roles you will meet later. In إِنَّ ٱللَّهَ, the particle inna makes the name of Allah mansub, so you read inna Allaha with a fatha.

Jarr: after prepositions and in possession

Jarr has two main causes. A preposition such as min (from), fi (in), bi (with) or li (for) puts the noun after it into jarr. And in a possessive pair (idafah), the second noun is always majrur: in رَبِّ ٱلْعَـٰلَمِينَ, "Lord of the worlds", the worlds are majrur because they complete rabb.

I'rab in the Qur'an: when one vowel changes the meaning

I'rab in the Qur'an matters most where the object comes before the doer, because then word order would mislead you and only the endings tell the truth. Two ayat show this clearly.

Read word for word in English order, this looks like "only fears Allah ... the scholars", and a careless reader might think Allah is the one who fears. The endings rule that out. ٱللَّهَ carries a fatha, so it is mansub: the object, placed first. ٱلْعُلَمَـٰٓؤُا۟ carries a damma, so it is marfu': the doer, placed last. The scholars are the ones who fear Allah. IslamQA's explanation of this ayah adds that putting the object first gives the meaning that none truly fear Allah except those with knowledge.

The same pattern again. إِبْرَٰهِـۧمَ ends in a fatha, so Ibrahim is the object, the one who was tried. رَبُّهُۥ ends in a damma, so his Lord is the doer, the One who tried him. The translation has to turn the sentence round ("Abraham was tried by his Lord") to keep that meaning in English. Commentators on this ayah say the object comes first to put the focus on the one who was tested, since it is already known that Allah is the One who tests.

Al-Fatihah gives you all the basics in four words. Al-hamdu is the subject, marfu' with a damma. Lillahi is the name of Allah after the preposition li, so majrur with a kasra. Rabbi describes Allah and follows Him into jarr. Al-'alamina completes the possessive pair "Lord of the worlds", so it is majrur too, but as a plural its jarr is shown by a ya (-ina) rather than a kasra.

Do verbs have i'rab too?

Verbs have i'rab only in the present tense (al-mudari'). Al-Ajurrumiyyah states the rule simply: the present tense verb is always marfu' until a particle of nasb or of jazm comes before it. Verbs never take jarr, and nouns never take jazm. The past tense and the command form have fixed endings and sit outside i'rab altogether.

In لَمْ يَلِدْ وَلَمْ يُولَدْ (112:3), "He neither begets nor is born", both verbs would normally end in a damma (yalidu, yuladu). The particle lam cuts that ending off, so they end on a sukun: lam yalid wa lam yulad. Jazm literally means "cutting", and you can hear why.

What is the difference between mabni and mu'rab?

A mu'rab word changes its ending with its role; a mabni (built) word keeps the same ending whatever its role. Most nouns and present tense verbs are mu'rab. Pronouns, words like "this" and "who", particles, past tense verbs and commands are mabni. A built word still has a role in the sentence: grammarians say it stands in the place of a case (fi mahall) even though its ending never shows it.

Some mu'rab words cannot show their ending, so the case is implied rather than heard, which is the taqdiran in the definition. Words ending in a long alif are the classic example. In 35:28, يَخْشَى (fears) is a present tense verb in raf', but no damma can sit on its final alif, so grammarians say its damma is implied. The role is still there; you simply cannot hear it.

How do duals and plurals show their case?

Duals and some plurals show their case with letters instead of short vowels. You have already met one: the -ina of ٱلْعَـٰلَمِينَ. The table gives the main patterns. Do not try to memorise it in one sitting; learn each row when you start meeting it in your reading.

Do Arabic speakers use case endings today?

Everyday spoken Arabic dialects mostly drop the case endings, but formal Arabic and the Qur'an keep them. When you recite, every ending is pronounced as written, except at a stop: when you pause on a word you stop on a sukun, so the final vowel falls away (and -an usually becomes a long a). That is a recitation rule, not a change of case. Learning i'rab also prepares you for texts printed without vowel marks, where you supply the endings yourself from your understanding of the sentence.

How do you start learning i'rab?

You start learning i'rab by making sure you can read the vowels and tell the three types of word apart, then practising the cases on short ayat you already know. These steps keep it manageable.

I'rab is the heart of nahw, the grammar of the sentence, so the bigger picture of how sarf and nahw differ is worth reading alongside this. If you are wondering how far grammar needs to go for your own goals, our guide on how much Arabic you need to understand the Qur'an sets out realistic levels. And because i'rab clicks fastest when someone checks your parsing as you go, you can find a Qur'an or Arabic teacher of your choice to work through ayat with you.