Idghaam (إدغام) literally means "merging" or "inserting one thing into another." In Tajweed, it refers to the merging of one letter into the letter that follows it so that the two become one emphasized letter. Idghaam is an essential rule that appears frequently throughout the Quran, and understanding its types is crucial for proper recitation.
The most common type is Idghaam of Noon Sakinah and Tanween, which is divided into two sub-types. Idghaam with Ghunnah (إدغام بغنة) occurs when Noon Sakinah or Tanween is followed by the letters ي، ن، م، و (grouped as ينمو). The noon merges into the following letter while maintaining a nasal ghunnah sound for two counts. Idghaam without Ghunnah (إدغام بلا غنة) occurs when Noon Sakinah or Tanween is followed by ل or ر, and the noon merges completely without any nasalization.
Idghaam Mithlain (إدغام متماثلين) occurs when two identical letters meet (e.g., two noon letters, two meem letters). The first letter merges into the second, and the second is pronounced with a shaddah. Idghaam Mutajaanisain (إدغام متجانسين) occurs when two letters from the same makhraj but with different sifaat meet, such as ت and د, or ت and ط. Idghaam Mutaqaaribain (إدغام متقاربين) occurs when two letters from close articulation points meet.
It is important to note that Idghaam of Noon Sakinah and Tanween only applies when the noon and the following letter are in two different words. If they are in the same word (such as الدُّنيا or بُنيان), the noon is pronounced clearly (Ith-haar) to avoid confusion. Our interactive quizzes test your ability to identify the correct type of Idghaam and apply it in practice.