This study tries to settle some rules for the law of pharyngeal sounds.
These rules rely on the existent live language usages. In order to put these rules, this study presents some information about the area of pharyngeal sounds, and the view of pre
vious and more recent researchers to pharyngeal sounds. After this, the study presents pharyngeals in comparison between Arabic and Semitic languages. Later, the study proposes the existence of a general rule that applies to all members of the group of those languages; where all Semitic languages are obligated with
this rule, except Arabic, in which the rule is applied optionally. This voluntary application of such a rule in Arabic resulted in the existence of many alternative forms much more than in other languages. The study has used two methods: The descriptive analytical and the comparative historical methods.
