What is a partly declining ism (mamnu' min al-sarf)?
In one line
Classical definition
Understand it
إِبْرَاهِيمُ / إِبْرَاهِيمَ / إِبْرَاهِيمَ. Three states, two endings. The kasra never comes, and neither does tanwin.
This is why a fatha is not proof of nasab. سَلَامٌ عَلَى إِبْرَاهِيمَ — إِبْرَاهِيمَ is in jarr, after عَلَى, and still wears a fatha.
The three primary categories
Every ism falls into one of three: fully declining, partly declining, or non-declining. The category decides how the i'rab is expressed — not what the i'rab is.
Two things bring the kasra back, and both are worth memorising: when the word takes الـ, and when it becomes a مُضَاف. فِي مَسَاجِدَ but فِي الْمَسَاجِدِ, and فِي مَسَاجِدِ الْعِرَاقِ.
Why an ism is prevented. Some are stopped by a single cause on its own, some only when two causes meet.
One cause is enough in three cases.
One cause is enough
| # | The cause | |
|---|---|---|
| 1 | the extended feminine alif — ـَاء | صَحْرَاءُ، عُلَمَاءُ، أَنْبِيَاءُ |
| 2 | the shortened feminine alif — ـَى | سُكَارَى، كُبْرَى |
| 3 | the ultimate plural pattern | مَسَاجِدُ، مَصَابِيحُ، تَمَاثِيلُ |
In these three the single cause stops the word on its own — no tanwin, and a fatha where a kasra would be expected.
Two causes must meet otherwise — being a proper name or an adjective, joined by one further cause.
Two causes must meet
| First cause | Joined by | |
|---|---|---|
| a proper name | femininity | فَاطِمَةُ، مَكَّةُ |
| an added alif and nun | عُثْمَانُ، رَمَضَانُ | |
| foreign origin | إِبْرَاهِيمُ، سُلَيْمَانُ | |
| the pattern of a verb | أَحْمَدُ، يَزِيدُ | |
| a blended compound | بَعْلَبَكُّ | |
| deviation from its original form | عُمَرُ | |
| an adjective | an added alif and nun | عَطْشَانُ |
| the pattern of a verb | أَحْمَرُ، أَكْبَرُ | |
| deviation from its original form | مَثْنَى، ثُلَاثَ |
Six ways for a proper name, three for an adjective. One cause alone is never enough here — both must be present.
How to spot it
In the Qur'an
The commonest mistake
Not every alif or hamza at the end makes an ism partly declining — and this is the commonest error students make.
أَنْبَاءٌ، أَسْمَاءٌ، اِبْتِغَاءٌ، فَتًى، عَصًا all end in an alif or a hamza, and every one of them is fully declining.
The reason is that the ending has to be the right kind. The hamza must sit after an added alif, and the alif must be the feminine alif — not one that belongs to the root, and not one that is part of the word's own pattern.
Learn the two feminine alifs, and this whole class of mistakes disappears.
Related terms
Common questions
Why would a noun refuse tanwin at all?
Because it carries two of the recognised causes at once — being a name and foreign, being a name and feminine, following a plural pattern, and so on. It is not arbitrary: the causes are a fixed list, and two are needed.
Next in the guideاَلْمَبْنِيّWhat is a non-declining ism (mabni)? →Updated