Gāndhārī is an early Middle Indo-Aryan language - a Prakrit - with unique features that distinguish it from all other known Prakrits. Phonetically, it maintained all three Old Indo-Aryan sibilants - s, ś and ṣ - as distinct sounds where they fell together as in other Prakrits, a change that is considered one of the earliest Middle Indo-Aryan shifts. Gāndhārī also preserves certain Old Indo-Aryan consonant clusters, mostly those involving v and r. In addition, intervocalic Old Indo-Aryan th and dh are written early on with a special letter, which later is used interchangeably with s, suggesting an early change to a sound, likely the voiced dental fricative ð, and a later shift to z and then a plain s. The Middle Prakrits typically weakened th to dh, which later shifted to h. Kharoṣṭhī does not render the distinction between short and long vowels, so the details of that feature are not known.
Phonology
In general terms, Gāndhārī is a Middle Prakrit, a term for middle-stage Middle Indo-Aryan languages. It only begins to show the characteristics of the Late Prakrits in the 1st century of the Common Era. The Middle Prakrit phonetic features are the weakening of intervocalic consonants: degemination and voicing, such as the shift of OIA *k to g. The most rapid loss was the dentals, which started to disappear completely even before the late period as with *t > ∅ as in *pitar > piu; in contrast, retroflex consonants were never lost. There is also evidence of the loss of a distinction between aspirates and plain stops as well, which is unusual in the Indo-Aryan languages. In Central Asian Gāndhārī, there is often confusion in writing nasals with homorganic stops; it is unclear if this might represent assimilation of the stop or the appearance of prenasalized consonants to the phonetic inventory.
Grammar
Gāndhārī grammar is difficult to analyse; endings were eroded not only by the loss of final consonants and cluster simplification of all Prakrits but also by the apparent weakening of final vowels "'to the point that they were no longer differentiated'". Nonetheless, there was still at least a rudimentary system of grammatical case. Verbal forms are highly restricted in usage due to the primary usage of longer texts to translations of religious documents and the narrative nature of the sutras but seem to parallel changes in other Prakrits.
Lexicon
The lexicon of Gāndhārī is also limited by its textual usage; it is still possible to determine unusual forms, such as Gāndhārī forms that show commonalities with forms in modern Indo-Iranian languages of the area, notably the Dardic languages. An example is the word for sister, which is a descendant of Old Indo-Aryan svasṛ- as in the Dardic languages, whereas all the Indo-Aryan languages have replaced that term with reflexes of bhaginī.
Rediscovery and history
Initial identification of a distinct language occurred through study of one of the Buddhist āgamas, the Dīrghāgama, which had been translated into Chinese by Buddhayaśas and Zhu Fonian.
Buddhist manuscripts in Gāndhāri
Until 1994, the only Gāndhāri manuscript available to the scholars was a birch bark manuscript of a Buddhist text, the Dharmapāda, discovered at Kohmāri Mazār near Hotan in Xinjiang in 1893 CE. From 1994 on, a large number of fragmentary manuscripts of Buddhist texts, seventy-seven altogether, were discovered in eastern Afghanistan and Western Pakistan. These include:
29 fragments of birch-bark scrolls of British Library collection consisting of parts of the Dharmapada, Anavatapta Gāthā, the Rhinoceros Sūtra, Sangitiparyaya and a collection of sutras from the Ekottara Āgama.
129 fragments of palm leaf folios of Schøyen Collection, 27 fragments of palm-leaf folios of Hirayama collection and 18 fragments of palm leaf folios of Hayashidera collection consisting of the Mahāyāna Mahāparinirvāṇa Sūtra and the Bhadrakalpikā Sūtra.
24 birch-bark scrolls of Senior collection consists of mostly different sutras and the Anavatapta Gāthā.
8 fragments of a single birch-bark scroll and 2 small fragments of another scroll of University of Washington collection consisting of probably an Abhidharma text or other scholastic commentaries.
Translations from Gāndhāri
Mahayana BuddhistPure Land sūtras were brought from Gandhāra to China as early as 147 CE, when the Kushan monk Lokakṣema began translating the first Buddhist sutras into Chinese. The earliest of these translations show evidence of having been translated from Gāndhārī. It is also known that manuscripts in the Kharoṣṭhī script existed in China during this period.
