Arabic letters are classified into to classes. Sonorous letters that when pronounce repression of breath is required so that the letter does not go with breath. This class includes nineteen letters. The second class is the susurrus that runs with breath. The susurrus class includes ten letters.

Sonorous		��������
Susurrus		��������

Another classification include nine classes as in the following table.

Throat		�������
Lahwia		�������
Relief Mouse		�������
Tip tongue		�������
Nateia		�������
Gingival		�������
Zalafia		�������
Verbal		�������-�������
Airily		��������

(Hamza ) is not included in this classification since it is considered as replacement to (Alef ), (Yaa ), and (Waw ). So the Arabic letters are counted 28 letters.