When did Coptic stop being used as an everyday spoken language?

Coptic, an Afro-Asiatic language representing the final stage of the ancient Egyptian language, gradually ceased to be an everyday spoken language following the 7th-century Arab conquest of Egypt.12

While it remained the medium of daily life for the majority of the population at the time of the conquest, the adoption of the Arabic language became a key factor for social and economic advancement under Arab rule. By the 12th century, Arabic had come into common use even among Christian Copts, and the Coptic language was relegated to a liturgical role within the Coptic Orthodox Church. Although the latest Coptic texts date from the 14th century, the language had already largely transitioned out of everyday spoken use by the 12th century.321