Noon Sakinah نون ساكنة

The four rules of Noon Sakinah are determined entirely by the letter that follows it. When followed by one of six throat letters (Hamza, Ha, Ain, Ha-emphatic, Ghain, Kha), Izhar applies and the Noon is pronounced clearly. When followed by six specific letters (Ya, Ra, Meem, Lam, Waw, Noon), Idgham applies and the Noon merges. When followed by Ba alone, Iqlab converts it. When followed by any of the remaining 15 letters, Ikhfa hides it.

Noon Sakinah can appear in two positions: within a word (tanween is similar but appears differently) or at the end of a word before the next word begins. The rules apply in both cases, though the word boundary affects specific applications — particularly for Idgham, where the two letters must be in separate words for the merging to occur. This word-boundary condition is a point of confusion for many students.

Tanween is closely related to Noon Sakinah and follows identical rules. Tanween is the double vowel mark (double fatha, double kasra, or double damma) that represents a Noon Sakinah at the end of an indefinite noun. When the Quran is read aloud, Tanween sounds exactly like a Noon Sakinah — so the same four rules apply. The visible difference is only in the written script: Tanween is marked on the noun itself, while Noon Sakinah appears as an explicit Noon letter with sukoon.

Mastering Noon Sakinah rules is a major milestone in Tajweed study. After learning them, students often experience a significant improvement in their recitation fluency and naturalness, as these rules govern some of the most common phonetic transitions in the Quran. The rules of Noon Sakinah directly explain many of the connected, flowing sounds that give expert recitation its characteristic smoothness.