What Is Idgham in Tajweed? Letters, Types and Exceptions

Idgham is the tajweed rule that makes recitation flow. Instead of saying a noon and then the next letter separately, the two blend into one smooth sound. Once you learn to hear it, you will notice it in almost every surah.

This guide explains what idgham is, its six letters, the two types, the important exceptions, and how to practise it.

What does idgham mean?

Idgham (إدغام) means "to merge" or "to insert one thing into another". In tajweed, it means that a noon sakinah (نْ) or tanween at the end of a word merges into the first letter of the next word, so that letter is pronounced as if it had a shaddah (a doubled letter).

The six letters of idgham

The six letters are collected in the word يَرْمَلُونَ (yarmaloon): ي ر م ل و ن.

They are divided into two groups:

1. Idgham with ghunnah — ي ن م و

The noon merges into the next letter, but its nasal sound stays and is held for about two counts.

• فَمَن يَعْمَلْ — famay ya'mal (Az-Zalzalah 99:7)
• خَيْرًا يَرَهُ — khayray yarah, tanween before ya (Az-Zalzalah 99:7)

Teachers note a small detail: before ن and م the merge is complete, while before ي and و a trace of the noon's ghunnah remains on the merged sound. A teacher will help you hear the difference.

2. Idgham without ghunnah — ل ر

The noon disappears completely into lam or ra, with no nasal sound at all.

• مِّن رَّبِّهِمْ — mir rabbihim (Al-Baqarah 2:5)
• هُدًى لِّلْمُتَّقِينَ — hudal lil-muttaqeen, tanween before lam (Al-Baqarah 2:2)

How to pronounce idgham correctly

1. Skip the noon's own position. Do not touch your tongue to the gum for the noon.
1. Go straight to the next letter and pronounce it with emphasis, as if doubled.
1. Add ghunnah only for ي ن م و, holding it for two even counts.
1. No ghunnah at all for ل ر.

Common mistakes

• Saying the noon clearly before the merge — min rabbihim instead of mir rabbihim.
• Adding ghunnah before ل or ر.
• Forgetting the ghunnah before ي and و, or making it too short.
• Applying idgham inside one word (see the exceptions).

The exceptions

• Inside one word, there is no idgham. In الدُّنْيَا, بُنْيَانٌ, قِنْوَانٌ and صِنْوَانٌ, the noon is read clearly so the words keep their meaning.
• يس وَالْقُرْآنِ and ن وَالْقَلَمِ: in the riwayah of Hafs, the noon at the end of these letter-names is read clearly before the waw.
• مَنْ رَاقٍ (Al-Qiyamah 75:27): in Hafs there is a short pause without breath (sakt) on the noon, so it does not merge into the ra.

Idgham compared with the other rules

How to practise

1. Read Surah Az-Zalzalah slowly and mark every idgham.
1. Say each pair twice: first the "wrong" way with a clear noon, then the merged way. Contrast trains your ear.
1. Count two even beats on each ghunnah.
1. Recite to a teacher — idgham is easy to understand but takes practice to apply at normal speed.

Next, learn about ghunnah in more detail, follow the whole sequence in our Tajweed guide, or practise with a teacher in our online Tajweed course.