Each nation can have its own language in Genesis 10 when the diversity of languages is also explained in Genesis 11 because
the two chapters are arranged in thematic, not chronological order; or
each region had its own language, plus the nations shared a common language.
The author explains that Japheth’s sons became the coastland people with their own languages (Gen. 10:5). When we reach Genesis 11:1 we learn that the whole earth had one language. How do we make sense of this apparent discrepancy?
There are two possible answers, and both are plausible. First, it could be that the author has arranged the primeval history thematically, as in creation-uncreation-recreation. We see this pattern beginning with creation, the fall into sin, followed by God’s grace over Adam and Eve. The pattern is repeated until we reach the blessing of God on Noah’s children. Noah’s children flourish due to the blessing and become the nations and languages of the world. Of course, this flourishing is followed by uncreation, as the people become arrogant at Babel, so God disperses them. If the account of Noah’s children becoming the nations came after the story of the flood, we would not think that Noah’s children flourished due to God’s blessing but due to judgment. Instead, the author is careful to arrange things such that there is a positive and a negative explanation for the diversity of languages and nations.
Another possible option is that the account is chronological, but the author has national languages and one common universal language in mind. We know from history that while many nations might have their own language, there is often a universal common language that diverse groups use to interact. These languages have included Sumerian, Greek, Latin, and English. We also notice that when the author refers to the languages of Japheth’s descendants in Genesis 10:5, he uses a different noun for language
than the term he uses for language
in Genesis 11:1. He also points out that the language in Genesis 11:1 had the same vocabulary. These pieces of evidence lend to the idea that the author has in mind a universal common language over and above each group’s national language.
In the end, both interpretative options have a high degree of plausibility.
Interpretation 1:
Genesis 10 and 11 are arranged in thematic, not chronological order.
Summary:
The author’s purpose is not to offer a highly accurate chronology at this stage in Genesis, but to explain the origins of sin, and God’s grace. Thus, the author repeats the theme of creation-uncreation-recreation. The author wants his readers to focus on the point that Noah’s descendants become the nations because God commands them to be fruitful and blesses them.
When God blesses Noah’s sons, Japheth and Shem, they become the nations of the world. Thus, the nations are the result of God’s guiding hand, who cares for people from every tribe and language. Diversity is the result of God’s blessing, and so diversity can be praised when it finds its roots and unity in God.
Advocates:
Bill Arnold
Arguments
Interpretation 2:
Each nation has its own language, plus it shared a common language.
Summary:
Genesis 10:1–32 explains how the nations originated, including the seafaring nations, the pastoral nomads, and urban civilization.5 These nations are defined by their own land, language, and family. At the same time there was a common language that these diverse nations shared, not unlike Latin in Europe during the Middle Ages, and English around the world in the twenty-first century.
Advocates:
Victor Hamilton
Arguments
5 From these the coastland peoples spread in their lands, each with his own language, by their clans, in their nations.