Gen 10 lists the various nations that came from the sons of Noah. In this list we find the following statement:

These were the sons of Ham, according to their families, according to their languages, in their lands and in their nations (Gen 10:20).

However in Gen 11 we read the earth had only one language:

Now the whole earth had one language and one speech (Gen 11:1).

There is a seeming contradiction between Gen 10, which speaks of many language groups and Gen 11, which says the earth was of only one language. How can we reconcile the two?

Not Chronological

As is true with many accounts in Scripture, the events are not listed in chronological order. Genesis tells of the disbursement of the different language groups throughout the world. It is a broad outline of where the various language groups settled. Gen 11, on the other hand, explains how these different languages came about—through the events at the tower of Babel. Thus we have no contradiction.