Idgham Mithlayn, Mutajanisayn and Mutaqaribayn Explained

You may already know idgham from the rules of noon sakinah and tanween. But idgham (merging) also happens between other letters. Tajweed scholars group these cases into three types, depending on how similar the two letters are: mithlayn, mutajanisayn and mutaqaribayn.

This guide explains each type in simple words, with Quran examples, in the recitation of Hafs from ‘Asim.

The basic idea

Idgham means merging a letter with a sukoon into the next letter, so you pronounce them as one doubled letter. In the Mushaf, the first letter usually has no sukoon and the second letter has a shaddah. That is your sign.

The three types depend on the relationship between the two letters:

1. Idgham mithlayn (two identical letters)

When a letter with sukoon is followed by the same letter with a vowel, you merge them. This is required.

• ٱضْرِب بِّعَصَاكَ → idrib-bi‘asak (2:60)
• وَقَد دَّخَلُوا → wa qad-dakhalu (5:61)
• يُدْرِككُّمُ → yudrikkumu (4:78)

If the two letters are meem or noon, you also hold a ghunnah of 2 counts:

• لَهُم مَّا → lahum-ma, with ghunnah

2. Idgham mutajanisayn (same place, different qualities)

These letters come from the same place in the mouth but have different qualities. In Hafs, idgham happens in these pairs:

The special case: ط before ت

When ط with sukoon comes before ت, the merging is partial (idgham naqis). The tongue moves to the ت, but you keep the heaviness of the ط. So basatta sounds a little fuller than a plain double ت. This is a common place for learners to make mistakes, so it is worth practising with a teacher.

3. Idgham mutaqaribayn (close letters)

These letters are close in place or quality. In Hafs, the main cases are:

• ل → ر: وَقُل رَّبِّ → wa qur-rabbi (17:24), بَل رَّفَعَهُ → bar-rafa‘ahu (4:158).
• ق → ك: أَلَمْ نَخْلُقكُّم (77:20). Scholars allow full merging (nakhlukkum), which is the more common reading, or partial merging that keeps a trace of the qaf.
• The lam of al before sun letters is also a type of mutaqaribayn. You already know it as the sun letters.

How to spot idgham in the Mushaf

1. Look for a letter with no sukoon right before a letter with shaddah.
1. Ask: are the two letters the same (mithlayn), from the same place (mutajanisayn), or close (mutaqaribayn)?
1. Read the two as one doubled letter.

If the first letter has a sukoon mark, it is read clearly — there is no idgham.

Common mistakes

• Pronouncing both letters, such as qad tabayyana instead of qat-tabayyana.
• Full merging in بَسَطتَ, losing the heaviness of the ط.
• Forgetting the ghunnah in ٱرْكَب مَّعَنَا and لَهُم مَّا.
• Merging after a long vowel, such as qalu-wwahum. A madd letter is never merged.
• Merging in بَلْ رَانَ, where Hafs has a short pause.

How to practise

1. Read the examples in this guide out loud, three times each.
1. Find them in your Mushaf and notice the missing sukoon and the shaddah.
1. Record yourself reading بَسَطتَ, أَحَطتُ and فَرَّطتُ, and compare with a teacher.

This is a more advanced topic. If you are just starting, first learn makharij (where the letters come from) and the heavy and light letters, because the three types depend on them. See the full order in our Tajweed guide, or learn with live correction in our online Tajweed course.