This tutorial deals with irregular verbs (as well as gerunds and derived nouns) whose final radical is a واو or a ياء. Such verbs are termed الأفعال الناقصة (sing. الفعل الناقص) and the rules that govern their conjugation are termed تعليل or إعلال.

For a more detailed picture of where this tutorial fits into Arabic morphology, consult the introduction to this section entitled Introduction to Arabic Morphology, and specifically the section on morphophonemic rules and weak verbs.

Introduction

In morphology, deficient verbs refers to those verbs whose final radical is a glide. Such verbs are termed ‘deficient’ because they instigate the application of very advanced rules brought about by the profuse occurrence of long vowels and diphthongs. These rules frequently result in the omission of letters from the verb; ergo the term ‘deficient’. Now the term ‘deficient verb’ should not be confused with its usage in grammar. In grammar, it refers to a class of sentential abrogators that are termed ‘deficient’ due to their inability to become the copula of a sentence.

In order to cover the chief rules associated with these verbs, we need only concern ourselves with deficient verbs from three verbal paradigms, as listed below. The rules given in the analysis of these examples will be sufficient in conjugating deficient verbs from any paradigm.

Specific Base Letters Used as an Example		Paradigm
غ، ز، و		فعَل / يفعُل
ر، م، ي		فعَل / يفعِل
ر، ض، و		فعِل / يفعَل

The Perfect Conjugations

The first two paradigms given above are those in which the middle letter is vowelled with a فتحة, and the third paradigm as well as the passive forms of all three paradigms are such that the middle letter is vowelled with a كسرة. Hence غزو and رمى will be dealt with separately and رضو and perfect passives will be dealt with separately.

Group 1

Below is what we’d expect of the perfect active conjugations for غزو and رمي.

رَمَيَ	غَزَوَ
رَمَيا	غَزَوا
رَمَيُوْا	غَزَوُوْا
رَمَيَتْ	غَزَوَتْ
رَمَيَتا	غَزَوَتا
...	...

Notice, however, that in each conjugation is a vowelled glide preceded by a فتحة. This is exactly the situation described in Rule 1 of Hollow Verbs. Rule 1 says that the glide should be changed to an الف.

رَمى	غَزا
رَمَيا	غَزَوا
رَمَاوْا	غَزَاوْا
رَمَاتْ	غَزَاتْ
رَمَاتا	غَزَاتا
...	...

There are four points to note now. The first is that Rule 1 only applies (potentially) to these five conjugations; the rest of the tables are not affected by Rule 1 and are therefore exactly as we would expect. Consult Hollow Verbs for a refresher if needed.