The articulation point of the 

These letters are pronounced from the top side of the tip of the tongue and the gum line of the two front upper incisors. The gum line is exactly where the gum meets the teeth. The part of the tongue used in these letters is a small part of the top of the tip, not any farther back than the very tip area. 

Common mistakes in these letters

The mistake that occurs most often in these letters is using the soft elevated area behind the gum instead of the gum line. The English “t” and “d” are articulated at this position which is further back in the mouth than the Arabic and . When these letters are emitted back too far, their sound gets heavy. Another problem that may occur in all of the letters in this group is not using just the top of the tip, but instead using a large portion of the top of the tongue. This is common in Urdu speaking Muslims as well as native English speakers, and it contributes to a heavy sounding letter. 

is a letter that has both tafkheem (heaviness) and sticks to the roof of the mouth. It is the strongest of all the letters of the Arabic language. The most common mistake (outside of the above mistakes) in this letter is not getting it strong enough, as well as not sticking most of the tongue up to the roof of the mouth while pronouncing it. Since this letter is not common to many languages, it needs practice to be proficient in its proper articulation. Listening to a known accomplished reciter can assist in learning the proper sound for  the .