This tidbit lesson concludes the section on the characteristics of the letters.  The last three characteristics that have no opposite are described here. 

Its linguistic definition: Repeating something once or more.

Its applied tajweed definition:

The light trilling of the tongue when pronouncing the  due to its tight articulation point.  The reciter should be careful not to exaggerate the repetition leading to the occurrence of more than one of the letter . 

Its letter :

Imam Al-Jazaree said the following about this characteristic:

Its linguistic definition : Spreading around
Its applied tajweed definition: Spreading the sound of the letter starting from its articulation point until it collides with the inner plates of the top teeth. 
Its letter:

The poem known as Al-Jazariyyah, stated the following about :

Its linguistic definition : Lengthening

Its applied tajweed Definition: It is the pushing of the tongue forward after it collides at its articulation point, and this is due to the influence of the compression of sound on it (the tongue) until the  tip of the tongue lightly touches the gum line of the two top front incisors. 

Note: The forward pushing is mechanical; the sound should not travel forward with this involuntary movement.  If the sound went forward with the tongue, the sound of  would then end up sounding like a , which is incorrect.  The lengthened sound of  is that of its characteristic of  and should be as long as  in any other letter that has .

Its letter: 

Al-Jazariyyah poem states:

Divisions of Characteristics According to Strength and the Weakness

All of the characteristics described in the last 8 lessons are divided into three groups as far as strength:

 The Strong Characteristics

، ، ، ، ،  ، ، ،  

The Medium Characteristics

، ،

The Weak Characteristics

، ، ، ،

We can by examining the different strengths of the characteristics determine the general strength of a particular letter.  For example, the letter   has all strong characteristics, and is considered the strongest letter in the Arabic alphabet.  The letter  on the other hand has all weak characteristics, so is a weak letter.