Key tajweed rules define how letters behave when they meet others or when they carry certain marks. The principal rules include Izhar (clarity), Idgham (merging), Iqlab (letter shift), Ikhfā (soft concealment), Sakt (brief pause), and Madd (vowel elongation).

• Izhar

Clear pronunciation of noon sakin or tanwīn before throat letters (ء, ه, ع, ح, غ, خ).

• Idgham

Merging of noon sakin or tanwīn into the following letter; with ghunnah for ن  و م ي, without ghunnah for ر ل.

• Iqlab

Changing noon sakin or tanwīn into a meem (م) sound when followed by ب.

• Ikhfā

Concealing noon sakin or tanwīn with a nasalized sound before the fifteen ikhfā letters (e.g., تُرْمُ).

• Sakt

A brief stop without full breath or vowel release, used for emphasis or clarity.

• Madd

Elongation of vowel sounds for 2, 4, or 6 counts, depending on whether it’s natural (asli) or requires a supporting sign (far‘i).

• Qalqalah

Echoing (“bouncing”) sound on the five qalqalah letters (ق، ط، ب، ج، د) when they carry sukun.

• Ghunnah

A nasal resonance, typically lasting two counts, occurring in rules like idgham with ghunnah and ikhfa.

• Waqf & Ibtida

Guidelines for where to pause (waqf) and how to restart (ibtida) recitation to maintain meaning and proper flow.