Read the following piece of information from The Encyclopedia of Language by David Crystal.

Egyptian is now extinct: its history dates from before the third millennium B.C., preserved in many hieroglyphic inscriptions and papyrus manuscripts. Around the second century A.D., it developed into a language known as Coptic. Coptic may still have been used as late as the early nineteenth century and is still used as a religious language by Monophysite Christians in Egypt.

What do you think are the reasons for the extinction of languages?

There are many reasons why languages are going extinct. Very often a dominant language which is not native to the locals displaces the main language. Other reasons include the genocide of entire races and poor preservation of cultural heritage and loss and damage of historical records.