119. The Derived Forms in general. The form of the Arabic verb we have been studying so far is the Base or Ground Form, that one which (theoretically, at least) expresses the essential notion of the verb at its simplest. In addition, however, every Arabic verb (both Standard and non-standard) is potentially capable of several pattern-modifications to indicate modifications of the essential meaning. Thus, while qatala is “to kill”, qattala is “to kill violently or on a large scale” (i.e. “to slaughter”, “to massacre”); and qātala is “to try to kill” (i.e. “to fight with”); taqattala and iqtatala, again, both mean “to fight (against each other)”. While there are 14 such Derived Forms in addition to the Base, no verb has them all; some have none or one, but most have something between three and six such forms in common use. Western Arabists number the forms conveniently in an agreed sequence from I to XV, and we shall adopt this practice. The most important are numbers II to VIII and X.

120. Advantages and limitations of the Derived Forms. The Derived Forms are often spoken of as though they gave Arabic a sort of mathematical exactness, that is as if the exact shade of meaning of every verb in a Derived Form could immediately be recognised once one knew the relevant formula; or as if every student of Arabic could “make up” his own Derived Forms to suit his purpose.