Idgham and it's types

Idgham — is the merging (assimilation) of two letters into one, followed by doubling, it happens with or without ghunna (nasalization).

There 3 types of merging (idgham):

1. Assimilation of two identical letters — الْإِدْغَامُ الْمُتَمَاثِلُ

2. Assimilation of two similar letters — الْإِدْغَامُ الْمُتَجَانِسُ

3. Assimilation of two letters with similar characteristics and points of articulation — الْإِدْغَامُ الْمُتَقَارِبُ

Assimilation of 2 identical letters which have the same points of articulation. The first letter has sukoon and the following one has a vowel, the result is: the first letter merges into the second one.

Examples:

An exception:

If the first of the two identical letters is a madd letter حُرُوفُ الْمَدٌّ, then the doubling is not allowed.

Note:

As for the ayah (28—29) in surah Al-Haqqa:

In this case the assimilation (idgham) is allowed and it can be read like this مَا لِيَهَّلَكَ, but a pause on the letter ـه is more preferable (without exhaling according to the rule of sakt).

Questions:

1. How many types of Idgham are there?

2. What is the assimilation of the two identical letters?

This is a fused pronunciation of two similar paired letters that coincide in the place of articulation but differ in some characteristics.

There are the following pairs of letters that are similar by their places of formation:

1. Idgham د to ت:

2. Idgham ت to د:

3. Idgham ت to ط

4. Idgham ط to ت

5. Idgham ذ to ظ

6. Idgham ث to ذ:

7. Idgham ب to م:

Questions:

1. What is the assimilation (merging or idgham) of two similar paired letters?

2. How many pairs are there that are similar by the place of formation of letters?

This is the assimilation of two letters that are close to each other in makhraj (the place of sound formation) and in some pronunciation properties.

There are the following pairs of letters close to each other in their place of formation:

1. Idgham ل to ر:

2. Idgham ق to ك:

Questions:

1. What is the assimilation of letters that are close to each other?

2. How many pairs of letters are there that are close in the place of formation?