Coptic is the last phase of the evolution of the Ancient Egyptians' language. With the coming of the Greeks and the introduction and spread of Christianity in Egypt, Demotic (which was an earlier phase of the Ancient Egyptian Alphabets and a much less pictographic form than Hieroglyphic and Hieratic, but still too complex and inaccessible for the growing needs of daily life) was found inadequate for the reproduction and rendering of the Christian Scriptures.
Thus, Egyptian scholars and scribes started a new system of transliterating purely Egyptian texts in Greek alphabet, instead of the syllabic script. But they soon realized that this alphabet could not cope with all the native sounds, and thus they solved the problem by means of adopting the last seven additional letters of the Coptic alphabet from their own original Demotic script.
The Coptic language may therefore be defined as the late Egyptian vernacular inscribed or transliterated in the Greek alphabet to which was added seven additional characters from Demotic.
It is very difficult to fix a precise date for the emergence of this new system. It must have been a rather long and gradual process before its final systematization. By way of illustration of this phenomenon, it may be interesting to note that the first known Egyptian document to be transliterated into Greek characters was written a century and a half before Christ. Though we cannot generalize on the basis of such isolated instances as this one, it can be regarded as indicative of later practices.
In the course of the later half of the second century AD, and with the steady progress of Christianity in Egypt, it may be assumed that Coptic was invariably used alongside Demotic and the latter was destined to replace the former altogether.
It is interesting to note that the Coptic language reflected the old Egyptian local dialects. Consequently, we can distinguish in Coptic the following main dialects: Bohairic (or Lower Egyptian), Saidic (or Upper Egyptian), Faiyumic and Akhmimic. The dialect used in the present-day church liturgies is the Bohairic.
It is possible that by the end of the second and the beginning of the third centuries, most of the books of the Bible had been rendered into Coptic. The oldest Biblical codex hitherto discovered contains on papyrus extensive portions of the Epistoes of St. Paul in Coptic, estimated to have been written around 200 AD. In fact, immense treasures have been found in Coptic written between the second and the fifth centuries, essentially though not exclusively Biblical and religious in character.
Coptic survived the shock of the Arab Conquest of Egypt in the seventh century, and necessarily continued to be the official language in state affairs and book-keeping by the native functionaries and the Arab rulers. In 706 AC, the Umayyad Viceroy Abdullah Ibn Abd El-Malik issued the decree of substituting Arabic for Coptic in all state affairs. Though his injunction could not be carried out in practice, it proved to be an incentive for the native scribe to learn the language of the conqueror and this resulted in the appearance of many bilingual documents in subsequent centuries. In those times of changing Arab Dynasties, Coptic persisted as a spoken and liturgical language until approximately the thirteenth century, with the emergence of native scholars who composed Coptic grammars in Arabic as well as Arabic-Coptic dictionaries to help in the preservation of that tongue.
Is Coptic altogether defunct?
This is a debatable question. Apart from the use of Coptic in church services, we are told that there are isolated villages in Upper Egypt with "family tradition about the pronunciation of Coptic". On the other hand, it would be an error to describe Coptic as a living language. What is certain is that Coptic has left its mark on the spoken Arabic of Egypt in two ways: firstly, in the residue of a vocabulary that is peculiar to Egyptian Arabic, and secondly, in the nature of the grammar of the vernacular which the early bilingual Copts carried with them.
Currently, the Sunday School Movement (SSM), under Church sponsorship, has been active in reintroducing classes in Coptic, in order to familiarize the Coptic youth with liturgical terminology and all manner of rituals derived from Coptic.