Didn’t everyone speak the same language until the Tower of Babel?
Here, I quote from Carol Hill’s article “A Time and a Place for Noah” (PSCF 53.1 (March 2001): 24-40.) “The possibility that before ca. 2500 B.C. all of Mesopotamia spoke one language (Sumerian) may have been the foundation for the statement found in Gen. 11:1: And the whole earth was of one language and one speech. After about 2500 B.C. (or about the time of Peleg and the tower of Babel), other languages such as Old Akkadian and Old Babylonian (Semitic languages), “overtook” the ancient Sumerian, and by 2000 B.C., it had become dead as a spoken language. The oldest historical indications of the Semitic language in Mesopotamia are the names of the scribes found in the archives of Fara (Shuruppak) and Tell Abu Salabikh, dated to ca. 2600-2500 B.C.” I, of course, have Adam and Eve speaking differently from my Sumerian-like people, because in my novel, they hail from the mountainous area above the plains.