Features of the phonological lesson among the ancient ArabsSibawayh as a model

There is no doubt that the linguistic intellectual system created by Al-Khalil Al-Farahidi was not the only one of its kind, but rather it is considered the launch of the actual systems of linguistic studies at that time, as is the case with the modern linguistic launch that emerged with de Saussure in the West. It is obvious that every theory that emerged contained shortcomings, and those shortcomings provide the opportunity to build another theory, which was characterized by a set of linguistic ideas that were followed by the emergence of the Al-Khalil school and then the school of his student Sibawayh, who started from the data of his teacher, and he referred to that in his book "The Book". Before delving into his linguistic arguments, as Al-Jahiz called them, we stop at the phonetic study, especially with Sibawayh, and from here we must stop at his personal and scientific biography. Who is this linguist? What did he provide to complete this linguistic cognitive circle? I will answer these questions and others in this research according to the descriptive analytical method.