Noon Sakinah & Tanween Rules: Izhar, Idgham, Iqlab, Ikhfa
The four rules of noon sakinah and tanween in tajweed (Izhar, Idgham, Iqlab and Ikhfa), with their letters and clear examples, plus the meem sakinah rules.
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When a noon sakinah (نْ) or tanween (ـً ـٍ ـٌ) is followed by another letter, one of four tajweed rules applies, decided entirely by which letter comes next: Izhar (clear pronunciation), Idgham (merging), Iqlab (conversion to a meem sound), and Ikhfa (hiding with a nasal sound). Learn which letters trigger each rule and you have one of the most useful parts of tajweed.
Noon sakinah is a noon with a sukoon (no vowel); tanween is the doubled-vowel ending that sounds like a noon sakinah. Both behave identically here, which is why the rules are taught together.
1. Izhar (clear pronunciation)
If the noon sakinah or tanween is followed by one of the six throat letters (ء ه ع ح غ خ: hamza, haa, ‘ayn, Haa, ghayn, khaa), you pronounce the noon clearly and distinctly, with no nasalisation held on it. This is called Izhar, meaning "to make clear." Example: in مِنْ خَوْفٍ, the noon before خ is pronounced plainly.
2. Idgham (merging)
If the noon sakinah or tanween is followed, in the next word, by one of the six letters in the word يَرْمَلُون (ي ر م ل و ن), the noon merges into that letter (within a single word, as in دُنْيَا, the noon stays clear). Idgham splits into two kinds:
- Idgham with ghunnah: with the letters ي ن م و (grouped as يَنْمُو). The noon merges and a nasal sound (ghunnah) is held for about two counts. Example: مَنْ يَقُولُ.
- Idgham without ghunnah: with the two letters ل and ر. The noon merges fully into the next letter with no nasalisation. Example: مِنْ رَبِّهِمْ.
3. Iqlab (conversion)
If the noon sakinah or tanween is followed by a single letter, ب (baa), the noon is converted into a hidden meem sound, pronounced with ghunnah. With only one trigger letter, it is the easiest rule to remember. Example: مِنْ بَعْدِ is read as if "mim ba‘di."
4. Ikhfa (hiding)
If the noon sakinah or tanween is followed by any of the remaining fifteen letters (everything not covered above), the noon is neither pronounced clearly nor fully merged. It is "hidden," articulated as a light nasal sound that leans toward the next letter, held for about two counts. Ikhfa has the largest group of trigger letters of the four rules, so you hear it often. Example: مِنْ قَبْلِ.
The whole system comes down to one question: which letter follows the noon sakinah or tanween? Six throat letters → Izhar; يرملون → Idgham; ب → Iqlab; everything else → Ikhfa.
The meem sakinah rules (a close companion)
A meem sakinah (مْ) follows the same mental model with three rules, called the "shafawi" (lip) rules because meem is a lip letter:
- Ikhfa Shafawi: when meem sakinah is followed by ب, hide the meem with a light nasal sound.
- Idgham Shafawi: when followed by another م, merge the two with ghunnah.
- Izhar Shafawi: when followed by any other letter, pronounce the meem clearly.
Seeing and hearing the rules
These rules are much easier to absorb when you can see them in a real verse and hear them recited. RecitID’s Tajweed colour-coded Mushaf highlights pronunciation rules by colour as you read, and per-verse audio lets you hear a qualified reciter apply them. For the full colour legend and what each colour means, see our tajweed colour codes guide.
Frequently asked
What are the four rules of noon sakinah and tanween?
Izhar (clear pronunciation, with the six throat letters ء ه ع ح غ خ), Idgham (merging, with the letters of يرملون), Iqlab (converting the noon to a meem sound, with the letter ب), and Ikhfa (hiding with a nasal sound, with the remaining fifteen letters).
What is the difference between noon sakinah and tanween?
Noon sakinah is the letter noon carrying a sukoon (no vowel). Tanween is the doubled short-vowel ending at the end of a word, which is pronounced like a noon sakinah. Because they sound the same, the same four rules apply to both.
Which rule is the most common?
Ikhfa applies to the largest group of letters: fifteen, against six each for Izhar and Idgham and one for Iqlab. How often each rule actually occurs depends on the passage, but the wide letter range is why you hear a light, held nasal sound before so many letters in recitation.
To see these rules colour-coded as you read, download RecitID for iOS and Android. The Tajweed Mushaf highlights the rules and lets you hear each one recited.
Related reading: qalqalah, the madd rules and memorising by listening.
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RecitID Editorial Team · Editorial
The people building RecitID: a small team of engineers, Arabic editors, and designers working on Quran identification, translation, and reading tools.
