I'rabThe three statescore term12,112+ in the Qur'an
Also written: Nasab · Nasb · Mansoob · Mansub · Mansoub
In one line
Nasb (نَصْب) is the straight state of i'rab; a word standing in it is called manṣūb (مَنْصُوب), and twelve roles put an ism there.
Definition — the four divisions of i'rab
وَأَقْسَامُهُ أَرْبَعَةٌ: رَفْعٌ وَنَصْبٌ وَخَفْضٌ وَجَزْمٌ. فَلِلْأَسْمَاءِ مِنْ ذٰلِكَ الرَّفْعُ وَالنَّصْبُ وَالْخَفْضُ وَلَا جَزْمَ فِيهَا، وَلِلْأَفْعَالِ مِنْ ذٰلِكَ الرَّفْعُ وَالنَّصْبُ وَالْجَزْمُ وَلَا خَفْضَ فِيهَا.
“Its divisions are four: rafa, nasab, khafd (jarr) and jazm. Of these, nouns take rafa, nasab and khafd, and there is no jazm in them; verbs take rafa, nasab and jazm, and there is no khafd in them.”
(الآجرّومية)
Key words in the Arabic
وَأَقْسَامُهُ أَرْبَعَةٌits divisions are four
خَفْضkhafd — the older name for jarr
وَلَا جَزْمَ فِيهَاand there is no jazm in them (nouns)
وَلَا خَفْضَ فِيهَاand there is no khafd in them (verbs)
Understand it
نَصْب (nasab) is the name of the state; مَنْصُوب (manṣūb) is what you call a word standing in it.
For most isms nasab shows as a fatḥa — مُسْلِمًا (musliman), الْمُسْلِمَ (al-muslima). When the word is indefinite and carries two fatḥas, an alif is written after it — كِتَابًا — except after a tā' marbūṭa (جَنَّةً) or after an alif with hamza (سَمَاءً).
What puts a word in nasab
Twelve roles put an ism into nasab — more than either of the other two states, which is why nasab is the longest chapter of any nahw book.
Other categories express nasab by letters instead: the dual with ـَيْنِ, the sound masculine plural with ـِينَ, the sound feminine plural with a kasra — مُسْلِمَاتٍ — and the five nouns with an أَلِف.
How to spot it
Recognition test
A fatḥa or tanwīn fatḥ at the end is the usual sign — but a partly declining word takes a single fatḥa in jarr too, so check the category before you decide.
Don't confuse it with
Like most Arabic grammar terms, نَصْب (nasab) was taken from everyday speech and then given one precise technical sense.
In everyday Arabic it means setting a thing upright, standing it straight.
نَصَبَ الْخَيْمَةَ (nasaba al-khaymata) — “he pitched the tent”
In Arabic grammar it means the state whose sign is the upright stroke above the letter, the fatḥa, and what stands in place of it.
Related terms
Next in the guideاَلْجَرّWhat is jarr (al-jarr), and what is a majrūr word? →
Draft · awaiting final review. This page is being rewritten and checked against the source books.