What is Tafkheem?
Tafkheem is an Arabic term meaning "to make thick" or "heavy". In Tajweed, it refers to elevating the back of the tongue towards the roof of the mouth while maximizing the space in the mouth to produce a deep, resonant sound.
The 7 Heavy Letters
These letters are grouped in the phrase: "Khussa Daghtin Qidh" (خُصَّ ضَغْطٍ قِظْ). They must always be pronounced heavily, regardless of the vowel (Fatha, Kasra, or Damma) on them, though the degree of heaviness varies.
خKhaa
صSaad
ضDaad
غGhain
طTaa
قQaaf
ظThaa
Common Mistakes to Avoid
Mistake:
Smiling while pronouncing heavy letters. This flattens the tongue and thins the sound.
Correction:
Keep the mouth vertically open or neutral. Raise the back of the tongue. Feel the sound resonating in the mouth cavity.