What is a maqsur ism, and why does it never change?
In one line
Definition
Key words in the Arabic
Understand it
الْفَتَى، الْهُدَى، الْعَصَا، الْمُصْطَفَى، مُوسَى، الضُّحَى — every one ends in a permanent alif, and every one looks identical in all three states.
The maqsur — how it shows its i'rab
| State | Sign | Example | |
|---|---|---|---|
| rafa | damma | جَاءَ الْهُدَى | ja'a al-huda |
| nasab | fatha | رَأَيْتُ الْهُدَى | ra'aytu al-huda |
| jarr | kasra | بِالْهُدَى | bi-l-huda |
Nothing moves. All three signs are estimated on the final alif, which cannot carry a vowel at all.
The special cases
Seven categories that express i'rab their own way — by letters instead of vowels, or by not showing it at all.
The i'rab has not vanished. It is مُقَدَّرَة — estimated: present in the grammar, impossible to pronounce. The books name the impediment exactly: التَّعَذُّر (al-ta'adhdhur), sheer impossibility. An alif cannot carry a vowel at all.
So the parsing is written out in full: fa'il in rafa, its sign an estimated damma on the final alif, prevented from appearing by impossibility.
How to spot it
In the Qur'an
Don't confuse it with a mabni word
A maqsur ism is not mabni, however much it looks it.
هٰذَا never changes because that is simply what the word is. It is مَبْنِيّ, and it has no i'rab to show.
مُوسَى never changes because an alif physically cannot carry a vowel. It is مُعْرَب — it has an i'rab in each state; the alif just cannot pronounce it.
The classical definition of bina' rules maqsur out in four words: لِغَيْرِ اعْتِلَالٍ, fixed for a reason other than a weak letter. Here the weak letter is the whole reason.
Related terms
Common questions
How do I do i'rab on a word whose ending never moves?
Exactly as on any other word, then add that the vowel is estimated. The role determines the case; the fixed alif simply prevents that case from showing. Nothing about the analysis changes except its last line.
Next in the guideاَلِاسْم الْمَنْقُوصWhat is a manqus ism, and why does its fatha show? →Updated