Grammar term · Sarf · morphology
مُضَعَّف
muda''af
Doubled (geminate) root
Sarf · morphologyRoot soundness (sihha/i'lal)core term942+ in the Qur'an
In one line
The doubled root: two identical radicals written as one letter with shadda — مَسَّ, رَدَّ, ظَنَّ.
Classical definition
المُضَعَّفُ مَا كَانَ فِيهِ حَرْفَانِ مِنْ جِنْسٍ وَاحِدٍ، عَيْنُهُ وَلَامُهُ أَوْ فَاؤُهُ وَعَيْنُهُ.
“The doubled verb is that which contains two letters of the same kind — its middle and last radical, or (in four-letter roots) its first and third.”
(بتصرف من شذا العرف)
Key words in the Arabic
مِنْ جِنْسٍ وَاحِدٍof one and the same kind
عَيْنُهُ وَلَامُهُits middle and final radicals
Understand it
When 'ayn and lam are the same letter, Arabic merges them under a shadda: مَسَّ is really مَسَسَ. The merge holds while endings begin with vowels (مَسَّهُ) but unfolds before consonant-starting endings — مَسِسْتُ, 'I touched' — and it is exactly this merging-and-unfolding that makes the mudaaf worth its own category. In jazm two options coexist: يَمْسَسْ and يَمَسَّ.
How to spot it
Recognition test
A verb whose dictionary form shows a final shadda: mudaaf. Expect the doubled letter to unfold whenever a sukun-starting pronoun (تُ، نَا، نَ) attaches.
In the Qur'an
أَنِّى مَسَّنِىَ ٱلضُّرُّ
Al-Anbiya 21:83 — “Indeed, adversity has touched me”
مَسَّ — 'ayn and lam are one letter under the shadda: a mudaaf root (مسس), here followed by nun al-wiqaya.
Forms it takes
مضعف
Related terms