Ilal al-Tathniya
- Author died
- 392 AH
- Editions
- Maktabat al-Thaqāfah al-Dīniyyah
Ilal al-Tathniya (The Rationale of Dualization) is a grammatical treatise written by the Arab grammarian Ibn Jinni (d. 392 AH / 1002 CE) that examines the phonetic and morphosyntactic rationale ('ilal) governing the dual form (al-tathniya) in Arabic .
Subject Matter and Scope
The treatise focuses on the theoretical justification of how dual nouns and dual verbs operate in Arabic grammar . Ibn Jinni addresses the classification of the inflectional letters added to form the dual (the alif in the nominative case and the ya' in the accusative and genitive cases), the role and vocalization of the appended nun, the dual forms of vague nouns (al-mubhamat, such as demonstratives and relative pronouns), and the inflection of dual present-tense verbs .
Grammatical Debates and Positions
The Dual Letters and Inflection
Ibn Jinni outlines the doctrinal disagreements among Arabic grammarians regarding the nature of the alif and ya' in dual nouns:
- Sibawayh, followed by Abu Ishaq al-Zajjaj, Ibn Kaysan, Abu Bakr ibn al-Sarraj, and Abu Ali al-Farisi—a position maintained by Ibn Jinni himself—held that the alif (and the ya' in the genitive and accusative) is the letter of inflection (harf al-i'rab) rather than an estimated vowel or the inflection itself .
- Abu al-Hasan al-Akhfash and Abu al-Abbas al-Mubarrad argued that the letter is neither the inflection nor the letter of inflection, but rather an indicator of inflection (dalil al-i'rab) .
- Abu Umar al-Jarmi agreed with Sibawayh that it is the letter of inflection, but maintained that its alternation (inqilab) constitutes the inflection itself .
- Al-Farra', Abu Ishaq al-Ziyyadi, and Qutrub held that the letter itself is the inflection (i'rab) .
To answer objections against classifying the alif as a letter of inflection—specifically why it transforms into a ya' unlike normal radical final consonants—Ibn Jinni notes that undisputed letters of inflection also alternate, citing the alif in kila and kilta when attached to pronouns, as well as the alternating endings of the six nouns (al-asma' al-sitta, such as abuk and dhu mal) . He quotes Abu Ali al-Farisi's argument that if the waw in dhu and fu were not the letter of inflection, the singular noun would be reduced to a single radical letter .
The Role and Vocalization of the Nun
Ibn Jinni upholds the view of Sibawayh that the suffix -nun is added to compensate for the short vowel (haraka) and nunation (tanwin) that the singular noun receives, which are blocked from appearing on the dual's long vowels (alif and ya') .
Regarding its vocalization, the dual nun is given a kasra, whereas the sound masculine plural nun takes a fatha, in both cases to resolve the cluster of two vowelless letters (iltiqa' al-sakinayn) . Ibn Jinni explains that the kasra (a heavy vowel) balances the light preceding alif in the dual, while the fatha (a light vowel) balances the heavy preceding waw in the plural . He also notes a dialectal variant among certain Arabs who pronounce the dual nun with a fatha in the genitive and accusative cases by analogy with words like ayna and kayfa .
Dual Demonstratives and Relatives
In the section on vague nouns (al-mubhamat), Ibn Jinni argues that demonstrative pronouns (such as hadha) and relative pronouns (such as alladhi) are not truly dualized in the strict grammatical sense, because dualization properly applies only to indefinite nouns (nakirat) . He refutes the Kufan view regarding forms such as dhan, demonstrating that the alif in dhan is the dual suffix itself while the original alif of dha has dropped out, as evidenced by its turning into a ya' in the oblique cases .
Dual Verbs
In treating imperfect verbs conjugated for the dual (such as yaqumani), Ibn Jinni demonstrates that neither the mim, the alif, nor the nun can function as the letter of inflection . Consequently, the inflection in such verbs does not have the strength of primary vocalic inflection; instead, the nun acts as a deputy and indicator standing in place of the damma found in the singular form yaqumu .
Answer updated