Much like Parshat Breishit tells two stories of creation, Parshat Noah gives two explanations for the existence of different languages.
The obvious explanation appears in the story of the Tower of Babel. After the Flood ended, "[e]veryone on earth had the same language and the same words." Genesis 11:1. The people gathered and resolved to build a tower; G-d was displeased and said, "If, as one people with one language for all, this is how they have begun to act, then nothing that they may propose to do will be out of their reach. Let us, then, go down and confound their speech there, so that they shall not understand one another’s speech." Genesis 11:6-7. Read literally, God created different languages to prevent people from scheming together against God.
The last verse in the account of the Tower of Babel presents a different explanation. "That is why it was called Babel, because there the Lord confounded the speech of the whole earth; and from there the Lord scattered them over the face of the whole earth." Genesis 11:9. Read in order, this verse suggests that God first created different languages, then scattered people across the earth. In actuality, the cause and effect are reversed. Linguistic variation, the development of new languages, occurs when people are spread out. Language also changes over time. For example, the grammar of Biblical Hebrew is different from Modern Hebrew. And while we can understand Shakespeare, and even much of Chaucer, English has clearly changed over the centuries. As language changes over time, the speech of separated groups will change in different ways, and perhaps ultimately develop into mutually-incomprehensible languages. Latin, for instance, diversified into different languages, French, Spanish, Italian, and so forth – based on geographical region.
So it is with the descendants of Noah. The genealogies in Genesis, Chapter 10 tell us that Noah’s descendants developed into nations, which "branched out over the earth after the Flood." Genesis 10:32. As a natural result of geographical dispersion, and limited regular contact between different groups due to distance, the groups ultimately developed different languages. Linguistics pays tribute to the Biblical account by naming language families after Noah’s descendants: the Semitic language family (which includes Hebrew and Arabic) is named after Noah’s son Shem; the Hamitic language family (centered in Northern Africa and which includes Egyptian and Berber) is named for Noah’s son Ham; the Cushitic family (which includes Oromo and Somali, spoken in the Horn of Africa) is named after Ham’s son Cush.
The Tanakh is rich in stories about language itself. For example, Chapter 12:5-6 of Judges confirms the existence of different accents, specifically the existence of certain sounds in one variety of speech but not another. After the Gileadites defeated the Ephraimites in war, the Gileadites used the word "shibboleth" (spelled with the letter shin) as a password to prevent Ephraimites from crossing into their territory. The narrative tells us that Ephraimites could not pronounce the sound "sh." Instead, the Ephraimites would say "sibboleth" (spelled with the letter samekh). The use of samekh instead of the letter sin is a literary device to underscore the difference in pronunciation, especially for the benefit of readers whose language does not contain both "sh" and "s" sounds. The Gileadites were able to hear the difference between the sounds "sh" and "s," and so identify Ephraimites by their accent.
Language, like any form of human behavior, is complex. In order to speak and understand each other, we must simultaneously keep track of syntax (word order) and semantics (word meaning). We must also produce and perceive different words, whether our language is spoken aloud or signed. On top of all of those variables, we must use language appropriately in a variety of social settings. A conversation with the boss calls for more formal speech, while we use slang in a casual conversation with friends. No language is more or less complex than any other language; rather, different languages have different features. Sign languages are no less complex than other languages; all have rules of grammar and a vocabulary of words with defined meanings. Languages vary by region, and all languages change over time. The use of language is a natural human social behavior.
How, then, can we understand the theological significance of the story of the Tower of Babel? Many commentators have seen the imposition of different languages as a fitting punishment for humanity’s sin in building the Tower, a symbol of immorality and materialism. Rabbi Ismar Schorsch sees a parallel between the switch from one to many languages and the descent of humanity from monotheism (before the Flood) to polytheism (after the Flood). "Polytheism is but a subset of the deviations which constitute human depravity. To move from one to many languages implies the move from one to many Gods. Mired in things material we lose sight of the spiritual. Rebellion against God subverts the destiny envisioned for us at the beginning as partners in the sustaining of creation." (http://learn.jtsa.edu/topics/parashah/5763/noah.shtml) However, the existence of different languages is not, in itself, a bad thing. Rather, the ends for which we use language can be positive or negative. Instead of using language for negative, scheming purposes, we should use it for positive and meaningful purposes.
Shabbat Shalom.