Grammar term · I'rab · 'Alāmāt al-i'rāb — the signs

Elision of nun

hadhf al-nun
حَذْف النُّون
I'rab'Alāmāt al-i'rāb — the signsadvanced term1,876+ in the Qur'an
In one line
Elision of the nun — the nasab and jazm marker of the five verbs.
Classical definition
وَأَمَّا حَذْفُ النُّونِ فَيَكُونُ عَلَامَةً لِلنَّصْبِ فِي الْأَفْعَالِ الْخَمْسَةِ الَّتِي رَفْعُهَا بِثَبَاتِ النُّونِ؛ وَأَمَّا الْحَذْفُ فَيَكُونُ عَلَامَةً لِلْجَزْمِ فِي الْفِعْلِ الْمُضَارِعِ الْمُعْتَلِّ الْآخِرِ، وَفِي الْأَفْعَالِ الَّتِي رَفْعُهَا بِثَبَاتِ النُّونِ.
“Elision is the marker of jazm in the present verb with a weak final letter, and in the verbs whose rafa is by retention of the nun.”
(الآجرّومية)
Understand it

The same missing nun serves two masters: after a nasab particle (أَن تَفْعَلُوا) and after a jazm particle (لَمْ تَفْعَلُوا) the five verbs look identical — the governor before them tells you which state struck. A vanished nun at these endings is never an error in the text; it is grammar happening.

How to spot it
Recognition test
A five-verb form without its nun — find the أَنْ / لَنْ / لَمْ / لَا that removed it.
Related terms
Next in the guideحَذْف حَرْف الْعِلَّةElision of weak letter →
Draft · awaiting final review. This page is being rewritten and checked against the source books.