Every Language Has Two Histories: Family Trees and Friend Groups

One of my favorite things about teaching linguistics is watching students discover that languages have histories much like people do. We often think of a language as belonging to a particular "family," but that is only part of its story.

Recently, a student repeated something another instructor had said: that Aramaic was "a dialect of Greek." Rather than simply responding, "That's incorrect," I asked the class a different question:

Why might someone think that?

That question led us into one of the most useful distinctions in historical linguistics that I find myself returning to again and again because it explains so many apparent contradictions. Every language has (at least) two histories:

• its family tree (its ancestry), and

• its friend groups (its contact history).

Oddly enough, this insight became much clearer to me because I also work professionally as a genealogist.

Image: "Anglo-Saxon Migration in the 5th Century" by Notuncurious, via Wikimedia Commons (CC BY-SA 3.0).

Why Language Families Matter

Historical linguistics asks which languages descend from a common ancestor.

The answer is based on systematic evidence. Linguists compare regular sound correspondences, shared grammatical innovations, and inherited vocabulary to reconstruct relationships among languages. English belongs to the Germanic branch of the Indo-European language family. Spanish, Russian, Hindi, Greek, and Persian are also Indo-European languages, although they belong to different branches. Aramaic, however, belongs to the Semitic family, alongside Hebrew and Arabic. These relationships are not based on geography, politics, or writing systems. They are genealogical relationships much like biological family relationships. Just as cousins may look different after thousands of years of separate history, related languages may sound very different while still preserving evidence of their common ancestry. This family-tree model has been one of the great successes of historical linguistics because it allows researchers to reconstruct languages that were never written down and to trace language change across thousands of years.

Why Linguists Sometimes Disagree About Classification

Although language families are grounded in evidence, classification is not always straightforward.

Languages change continuously. Some branches are well documented while others have sparse historical records. Written evidence may be limited or absent altogether. Sometimes the evidence points clearly toward a common ancestor; other times it is incomplete enough that scholars debate exactly how languages are related.

There are also cases where languages influence one another so extensively through contact that borrowed features can obscure inherited ones. This is one reason linguists distinguish carefully between inheritance and borrowing. Inherited features tell us about ancestry while borrowed features tell us about interaction. Both matter but they answer different questions.

English: A Language with Many Friends

English is an excellent illustration of the inheritance + contact biography. Its ancestry is firmly Germanic. English shares its deepest genealogical relationships with languages such as German, Dutch, Frisian, Swedish, Danish, Norwegian, and Icelandic. Yet anyone who has looked at English vocabulary quickly notices that much of it does not "feel" especially Germanic because English has spent centuries interacting with neighboring languages. Old Norse contributed thousands of everyday words during the Viking period. Words like sky, they, their, them, take, give, and window entered English through contact rather than inheritance. After the Norman Conquest of 1066, French became the language of government, law, and much of the educated elite in England. Thousands more words entered English, including government, court, justice, beauty, language, and nation. Later, English borrowed extensively from Latin, Greek, Italian, Spanish, Hindi, Japanese, Nahuatl, and hundreds of other languages. None of these borrowings changed English's ancestry. English remained a Germanic language. Its family tree stayed the same even as its friend group expanded dramatically.

Aramaic: Two Different Histories

This brings us back to the classroom discussion. Greek and Aramaic are not members of the same language family. Greek belongs to the Indo-European family and Aramaic belongs to the Semitic family. From the perspective of ancestry, they are unrelated, and yet historically, they spent centuries interacting. Following the conquests of Alexander the Great, Greek became the dominant language of administration, trade, and scholarship across much of the eastern Mediterranean and Near East. At various times, many Aramaic speakers became bilingual, and Greek and Aramaic influenced one another in numerous ways.

The New Testament of the Christian Bible itself reflects this multilingual world of Greek and Aramaic contact. Although most of it was written in Greek, it preserves Aramaic expressions, names, and quotations. Daily life in the eastern Mediterranean involved constant interaction among multiple languages. So if someone notices strong historical connections between Greek and Aramaic, they are observing something real. But contact is not ancestry. Languages can become close neighbors without becoming relatives.

What Language Contact Teaches Us

Language contact is one of the most fascinating areas of linguistics because it reminds us that languages do not develop in isolation. Trade, migration, conquest, education, religion, intermarriage, and technology all create opportunities for languages to influence one another. Sometimes only a few words are borrowed. Sometimes entire sound systems or grammatical patterns spread across neighboring languages. Sometimes languages influence one another so extensively that scholars speak of linguistic areas, where unrelated languages come to share important structural features through prolonged contact rather than common descent. This perspective encourages us to think about languages as living social systems rather than static objects. Every language tells at least two stories: where it came from, and whom it has lived beside, and both stories matter.

Why This Distinction Matters Today

I find myself thinking about this distinction not only as a linguist but also as a genealogist.

Professional genealogists sometimes study what Elizabeth Shown Mills calls the FAN Club: a person's Friends, Associates, and Neighbors. These relationships often provide the clues that biological family relationships alone cannot explain. Languages have FAN clubs too. Understanding a language requires more than tracing its ancestry. It also requires understanding the communities it interacted with, the cultures it encountered, and the people who shaped its development. When we confuse these two histories, we can misunderstand both. When we separate them, we gain a richer picture of human history itself. The next time someone asks whether two languages are "related," it is worth asking another question first:

Do you mean related by ancestry or connected through history?

And together, they tell a coherent story about how humans communicate, migrate, trade, learn from one another, and build communities across time. Whether you're exploring language families through resources like Ethnologue, comparing structural patterns using WALS, reading about the spread of Hellenistic culture after Alexander the Great, or simply noticing similarities between the languages around you, remember this: every language has a family tree.

And every language has friend groups. Understanding both is what makes historical linguistics so endlessly fascinating.

Learn More

Language Classification & Genealogy

• Ethnologue – A comprehensive reference for the world's languages, including language families, speaker populations, and geographic distribution.

• Glottolog – An academic database maintained by the Max Planck Institute that provides detailed language classifications and bibliographic information.

Language Structure & Typology

• World Atlas of Language Structures (WALS) – Compare hundreds of structural features across thousands of languages.

Historical Linguistics

• Campbell, Lyle. Historical Linguistics: An Introduction. One of the standard introductory textbooks in the field.

Language Contact

• Heine, Bernd. 1994. Areal Influence on Grammaticalization. In Martin Pütz (ed.), Language Contact and Language Conflict, 55–68. Amsterdam: John Benjamins.

Historical Background

• Encyclopaedia Britannica: Alexander the Great.