Tajwid: Rules of Noon Sakinah and Tanwin

Tajwid — the science of reciting the Quran with precision and beauty — is an obligation upon every Muslim who recites Allah's book. Among its most important chapters is the study of the noon sakinah (a noon letter with a sukun, carrying no vowel) and tanwin (the double vowel endings that indicate an indefinite noun). These occur frequently throughout the Quran, and their correct pronunciation is governed by four clearly defined rules, each applicable depending on the letter that follows them.

What Are Noon Sakinah and Tanwin?

The noon sakinah is the letter noon bearing a sukun — meaning it has no short vowel following it. It may appear within a word or at the end of a word. Tanwin is the double damma, double fatha, or double kasra added to indefinite nouns — it is pronounced as a noon sakinah in sound even though it is not written as a separate noon letter. Both are governed by the same four rules: Idhar, Idgham, Iqlab, and Ikhfa. Knowing which rule applies requires identifying the letter immediately following the noon sakinah or tanwin.

Rule 1: Idhar — Clear Pronunciation

Idhar means "to make clear." It applies when the noon sakinah or tanwin is followed by one of six throat letters (huruf al-halq): hamzah, ha, 'ayn, ha (the lighter ha), ghayn, kha. When any of these six letters follow, the noon is pronounced clearly and distinctly, without any nasalization or merging.

Examples from the Quran:

• min 'ilmin — the noon is pronounced clearly before the 'ayn
• man amana — the noon is clear before the hamzah
• sami'un 'alim — tanwin before 'ayn: both pronounced clearly

The reason these six letters require idhar is that they are produced deep in the throat, and it is physically impossible to merge or nasalize the noon into them without a natural break. The throat articulation separates them.

Rule 2: Idgham — Merging

Idgham means "to merge." When the noon sakinah or tanwin is followed by certain letters, the noon is merged into the following letter. Idgham has six letters divided into two groups:

Idgham with Ghunnah (nasal resonance): The letters ya, noon, meem, waw — remembered by the word yanmu. When noon sakinah is followed by these four letters across a word boundary (not within the same word), the noon is merged completely and a ghunnah of two counts is held.

• min yaqul — the noon merges into the ya with ghunnah
• hudan wa-rahmatun — tanwin merges into waw with ghunnah

Idgham without Ghunnah: The letters lam and ra. When noon sakinah is followed by lam or ra, the noon merges completely with no ghunnah whatsoever. The merger is total and immediate, producing a strengthened lam or ra.

• min rabbika — the noon merges into the ra with no ghunnah
• min ladunhu — noon merges into lam, no ghunnah

Important note: When noon sakinah and the following letter are within the same word, idgham does not apply — the noon is pronounced clearly. Example: bunyanun — the noon and ya are in the same word, so idhar applies, not idgham.

Rule 3: Iqlab — Conversion

Iqlab means "to convert." It applies to only one letter: ba. When noon sakinah or tanwin is followed by ba, the noon is converted into a meem sound — but the meem is not fully pronounced; instead, a nasal sound (ghunnah of two counts) is held with the lips lightly closed. In the printed Quran, iqlab is indicated by a small meem written above the noon or tanwin, making it easy to identify.

• ambiya' — written as if noon, pronounced closer to meem with ghunnah before the ba
• sami'un basir — tanwin before ba: convert to nasalized meem sound

Rule 4: Ikhfa — Concealment

Ikhfa means "to hide." It applies to the remaining fifteen letters not covered by the previous three rules — including letters such as sad, dhal, tha, kaf, jim, shin, qaf, sin, dal, ta, zay, fa, ta, dad, and zha. When noon sakinah or tanwin is followed by any of these fifteen letters, the noon is held in a middle state: the tongue does not touch the articulation point of noon, a nasal sound (ghunnah) is held for two counts, and then the following letter is pronounced.

• min qabli — noon with ghunnah before qaf
• min kulli — noon with ghunnah before kaf
• jannatin tajri — tanwin with ghunnah before ta

Mastery of these four rules — Idhar, Idgham (with and without ghunnah), Iqlab, and Ikhfa — is the foundation of correct Quranic recitation for every student of tajwid. They are best learned through listening to and imitating a qualified teacher, since the oral tradition of Quranic transmission is itself the gold standard of learning and always has been.