Language > Sumerian
The ancient spoken language of the Sumer civilization was known as Sumerian and is classified as a language isolate. It is well known for establishing the first bilingual system with Akkadian. It should be noted the Sumerian written language known as Cuneiform is classified as a different language than the spoken one since it persisted to be used for thousands of years after the decline of Sumer and the most likely loss of the spoken language.
The influence of the language of Sumerian on Akkadian and vice-versa is immense all throughout early Mesopotamia and there appears great similarities between syntax, morphology and phonology. This has led scholars to conclude that the languages of Sumerian and Akkadian actually create a sprachabund or an area of linguistic convergence.
The first origins of the spoken Sumerian language are believed to be traced back to around 3350 BC to the ancient civilization of Sumer that existed in southern Mesopotamia. It would exist as a prevalent language until around 2000-1800 BC when it went extinct for good.
This is due to the conquering of Sumer by the Akkadian Empire and the prominence of the Akkadian language in the new empire. The Sumerian language existed in the educated and scholars of Mesopotamia until it finally died out from lack of use. Sumerian would be used as a classical but dead language much like that of Latin in the modern era.