This volume contains sixteen contributions from the fourth conference on the Foundations of Arabic linguistics (Genova, 2016), all having to do with the development of linguistic theory in the Arabic grammatical tradition, starting from Sībawayhi's Kitāb (end of the 8th century C.E.) and its continuing evolution in later grammarians up till the 14th century C.E. The scope of this volume includes the links between grammar and other disciplines, such as lexicography and logic, and the reception of Arabic grammar in the Persian and Malay linguistic tradition.