The characteristics of the letters are what differentiate letters from others that share the same articulation point.  If the student of the Qur’an is not applying all the characteristics of the particular letter he/she is articulating, it will sound either like a totally different letter, or will sound incorrect at the very least.  The correct application of the characteristics of the letters makes the letters clearer, and teaches the various timings of the saakin letters, a very important aspect to good Qur’anic recitation.  Studying the characteristics makes clear which letters are strong in make up, and which are weak.  From this it is clear that the study of the characteristics of the letters and their application is a very important part of tajweed.  Indeed, the application of the characteristics of letters is what differentiates a good reciter from an average one.  

Linguistic definition of characteristics:  What serves the purpose of describing the meaning.
This can be in the way of physical descriptions such as white and black, or can be abstract descriptions such as education. 

Applied definition of characteristics: The mode of demonstration of the letter when it occurs at its articulation point, which differentiates it from others (other letters) 

Two Divisions of Characteristics

       1.  Intrinsic or Basic Characteristics : These are characteristics that are part of the intrinsic make up of the letter and never leave the letter.  This is what will be discussed in this section over the next several tidbit lessons. 

       2.   Presented Characteristics : These are characteristics which are present in a letter in some cases, and not present in the letter in other cases.  An example of this would be  (or merging), or  (or making clear).  These are covered in other areas of the tidbit lessons, and not discussed in this section of lessons.

The Intrinsic or Basic Characteristics

There are ten intrinsic characteristics in pairs; each characteristic of the pair is opposite to the other characteristic in the pair.  There are also six singular characteristics that have no opposites.  Every letter has at least five characteristics, one of each of the pairs of opposites.  

Ten Characteristics that have opposites

These pairs (sometimes there is more than two in the pair) are those that each letter has one of each.  This means that every letter has at least five intrinsic characteristics that never leave the letter.  A letter can never have both characteristics in an opposing group, only one of the two (or three) in the group.  We will, insha’ Allah, over the next several tidbit lessons describe these characteristics and their application in recitation, as well as the six characteristics that do not have opposites.  The five groups of opposite characteristics that each letter has one each of is as follows:

There are also some characteristics that certain letters have which have no opposites.  The letters that have these characteristics therefore have more than five intrinsic characteristics.  These non-paired intrinsic characteristics are as follows:

Six Characteristics without Opposites

       1.  The Whistle 

       2.  The Softness 

       3.  The Drifting

       4.  The Repetition

       5.  The Spreading Around

       6.  The Lengthening