Genesis 10:5
5 By these were the isles of the Gentiles divided in their lands; every one after his tongue, after their families, in their nations.
(cf. 20, 31)— Why does this verse indicate that humankind had many languages when Genesis 11:1 says there was only one?
PROBLEM: Genesis 10:5; Genesis 10:20; Genesis 10:31 seem to suggest many dialects, which is an apparent conflict with Genesis 11:1 that clearly states, “the whole earth had one language and one speech.”
SOLUTION: These texts speak of two different times. Earlier, while maintaining their tribal distinctions, the descendants of Ham, Shem, and Japheth all spoke the same language. Later, at the tower of Babel (Genesis 11), God punished their rebellious attempt by confusing their speech. As a result, tribes could no longer understand one another, though possibly the subtribes and clans were allowed a mutually understandable language so they could still understand one another.