The Sumerian language of ancient Sumer (or, more accurately, Shumer) became extinct and was forgotten until the 19th century. It does not have any known affinities to other languages (though many theories, linking it to Hungarian, Basque, Etruscan and many other languages exist). This distinguishes it from other languages of the area such as Hebrew, Akkadian, which also comprises Babylonian and Assyrian, and Aramaic, which are Semitic languages.
Sumerian was the first known written language. The script, called cuneiform, meaning "wedge-shaped", was later also used for Akkadian. It was even adapted to Indo-European languages like Hittite (which also had a hieroglyphic script, as did the Egyptians) and Old Persian, though the latter merely used the same instruments, and the letter shapes were unrelated.
The language is agglutinative, as opposed to modern isolating languages like Chinese, in which word parts appear separated. Sumerian made heavy use of compounding. For example, the words for big and man are compounded for the Sumerian word for king, "lugal".