Earlier attempts of preservation of language (revitalisation) was the writing of the scalae in the 13th & 14th century by El-Sammanudi, and Ibn Kabbar.
In the late 19th century and early 20th century, the largest attempt of revival was at the hands of Claudius Labib, who wrote numerous educational books, magazines (Ain Shams), as well as typing many litirugical books, and writing the first Coptic-Arabic dictionary. This line of revival was continued with Pisenty Rizkallah, Maurice AbdelMessih and others where they have all started reviving Coptic as a spoken language. This conitnued with Fr Pigol Bassili & Abba Demetrius.
This attempt was the most successful in the 20th century albeit limited in the number of speakers. It was characterised by the utilisation of the Greco-Bohairic pronunciation with many variants. There is evidence of influence of French, English and Arabic on the syntax of Coptic instead of using traditional phrases in Coptic manuscripts, creating a Coptic pidgin.
It is also characterised by the markedly reduced number of Greek loanwords in favour of Coptic ones albeit obscure words, as well sometimes, favouring neologisms over using Greek loanwords.
Another feature was neologisms, which were invented by the necessity but, also at times to avoid using a Greek loanword or for lack of knowledge of the original word. Many neologisms were not grammatically sound as compared with classical Coptic.
While this attempt was the most successful in terms of producing a few bilingual speakers, it did not revive Coptic, but rather a pidgin form of Coptic. Another byproduct was a byproduct of malformed neologisms, poor grammatical constructs, and instability of pronunciation. In essence, since the emergence of Greco-Bohairic pronunciation, Coptic is being treated as a language for hobbyists and amateurs, with false folk etymology books, and a general attitude that Coptic is a constructed language that everyone is welcome to add words to it and reinvent it, which resulted in huge numbers of almost incomprehensible writings.
Later, there were books attempting to change grammar, and even the writing system and adopt Latin script, and the proposed outcome was closer to a new constructed language with a Coptic flavour.