The ismNumberadvanced term
Also written: Jam' · Broken plural · Sound plural · Plurals
In one line
The plural of plurals: after the alif come two letters (or three with a sakin middle) — مَسَاجِد, مَصَابِيح — and the
tanwin is gone.
Definition
هُوَ كُلُّ جَمْعِ تَكْسِيرٍ وَقَعَ بَعْدَ أَلِفِ تَكْسِيرِهِ حَرْفَانِ، أَوْ ثَلَاثَةُ أَحْرُفٍ أَوْسَطُهَا سَاكِنٌ.
“It is any broken plural in which two letters follow the plural alif — or three whose middle letter is sakin.”
(النحو التطبيقي)
Key words in the Arabic
أَلِفِ تَكْسِيرِهِthe alif of its breaking — the long a inside the plural
أَوْسَطُهَا سَاكِنٌthe middle one of which carries sukun
Understand it
Arabic's biggest plural shapes — مَسَاجِد، قَوَاعِد، دَرَاهِم with two letters after the alif; مَصَابِيح، مَفَاتِيح، قَوَارِير with three around a sakin — have reached the 'utmost' of plural form: no further plural can be built on them. That fullness costs them their tanwin: the pattern is mamnu' min al-sarf, so jarr appears as fatha. One الْ or an idafa restores the kasra: فِي الْمَسَاجِدِ.
How to spot it
Recognition test
Alif in the middle, then two letters (or three with a silent middle), no tanwin possible: read jarr-with-fatha until the word carries الْ or is
mudaf.
In the Qur'an
وَلَقَدْ زَيَّنَّا ٱلسَّمَآءَ ٱلدُّنْيَا بِمَصَٰبِيحَ وَجَعَلْنَٰهَا رُجُومًا لِّلشَّيَٰطِينِ ۖ وَأَعْتَدْنَا لَهُمْ عَذَابَ ٱلسَّعِيرِ
Al-Mulk 67:5 — “And we have, (from of old), adorned the lowest heaven with Lamps, and We have made such (Lamps) (as) missiles to drive away the Evil Ones, and have prepared for them the Penalty of the Blazing Fire.”
مَصَٰبِيحَ after بِ should show kasra — instead a fatha and no tanwin: muntaha al-jumu' is mamnu' min al-sarf.
Don't confuse it with
The name is about shape, not about size. It does not mean “the biggest plural”.
It means a broken plural has reached the furthest pattern the language builds: after the plural alif come two letters (مَسَاجِد) or three with a sākin in the middle (مَصَابِيح).
Reaching that shape has one consequence, and it is an i'rab one — the word is mamnūʿ min al-ṣarf: no tanwīn, and fatḥa where you would expect kasra.
Related terms
Common questions
Why does this plural lose its tanwin?
Because the pattern itself is one of the causes that block tanwin. It has nothing to do with the meaning, or with being plural — the shape alone is enough to make the word refuse tanwin and take a fatha where you would expect a kasra.
Next in the guideإِعْرَاب الِاسْمI'rab →
