Question: One language or many languages?
Genesis 11:1,6-9 said that in the days of Babel, generations after the Flood, the world had one common language. God "confused the tongues" to create many. But, in Genesis 10:5, prior to Babel, the Bible speaks of many "nations", each with its own language.
Response: Genesis 10:5 isn't speaking about the time of Javan, but of the time of his future descendants. There is no contradiction because while Javan lived before the time of Babel, his descendants lived at a different time.