The term ʾaṣl is primarily used as one of the major tools of analysis in Arabic grammatical theory. It is first encountered in the Kitāb of Sībawayhi (d. 180/796) where it occurs 569 times (Troupeau 1976 sub ʾṢL), all of which, with the exception of four instances, indicate a methodological notion. Although the term itself may be generally translated as ‘origin’, ‘principle’, or ‘base’, it is used in a variety of specialized senses, the most basic of which are (for use by Sībawayhi, see Baalbaki 1988:163–164):

i.

The form, pattern, case ending, etc. which agrees with the qiyās, that is, wit…