Introduction

Derivational morphology creates word stems, or lexemes. It builds and enlarges the lexicon so that concepts may find expression within a language. Sometimes the process of derivation changes a word’s form class (e.g., creating an adjective from a noun, such as tuunis-iyy ‘Tunisian’ from tuunis ‘Tunisia’); sometimes it changes the subclass of a word (creating a transitive verb from an intransitive base, e.g., ʔadxala ‘to insert’ from daxala ‘to enter’). It affects almost all form classes or syntactic categories except those that are closed, such as function words (prepositions, conjunctions, particles). In Arabic, systematic derivation of words from lexical roots is at the heart of the word-creation system, and remains the distinctive feature of Arabic morphology. The fact that Arabic word stems consist primarily of discontinuous morphemes (interlocked roots and patterns) has been of substantial interest to morphological theory in general.

Derivational morphology can be expressed in terms of Word Formation Rules (WFRs). “A basic assumption … is that WFRs are rules of the lexicon, and as such operate totally within the lexicon. They are totally separate from the other rules of the grammar, though not from the other components of the grammar. A WFR may make reference to syntactic, semantic, and phonological properties of words, but not to syntactic, semantic, or phonological rules” (Aronoff 1976: 46). It is also the case that “derivational markers will be encompassed within inflectional markers” (Aronoff 1976: 2). That is, derivation applies to word-stem formation, creating a lexical unit. Inflectional markers are subsequently added to word stems when words are used in context. Derivation – in other words – is prior to inflection. Or, as Aronoff remarks, “Lexeme formation intrinsically feeds inflection” (1994: 127).