One of my more obscure interests is a fascination with the history of languages and their origins and development. For a long time people have sought to make connections between various languages in seeking to discover how it is that language isolates are connected to other languages or how it is that certain connections between languages that seem as divergent as English and Hebrew exist. In order to understand these matters it was not only necessary to compare languages as they now exist but to reconstruct past languages to see how it is that certain sounds changed over the course of thousands of years to get to the present day.
This task requires a fair amount of effort. For example, as an English speaker I speak a language that is part of the Indo-European family, a family that includes a great many languages spoken over the entire world, with numerous sub-families. English is a part of the Germanic sub-family of the Indo-European family, with a heavy influence from the Norman French that was spoken and a tendency to borrow words pretty heavily from other languages. There are at least three forms of written English going back over the last 1300 years or so, after which one can trace English back to a related set of West Germanic languages, and then from there to the Germanic subfamily as a whole. At this point one can compare the Germanic subfamily with various other related subfamilies of the Indo-European family, including the Italic languages, the Celtic languages, the Baltic languages, the Slavic languages, the Illyrian languages, the Greek languages, the Anatolian languages, the Indo-Iranian languages, and Tocharian, an obscure and extinct language of Central Asia. From there one can build up a language called Proto-Indo-European from a period of more than 5,000 years ago.
It must be admitted that this task does not only work for English and its cousin languages, but is something that can also be done and has also been done for a great many other languages. There are a reasonable number of language families that exist in the world. The Finno-Ugric language family includes Finnish, Estonian, Hungarian, various related languages, including Samoyed and a few other languages in the Urals, and some extinct languages from Crete and Anatolia. The Afro-Asiatic family includes Hebrew, Aramaic, Arabic, Coptic, Berber, and languages spoken in Ethiopia and surrounding areas. The Turkic languages are spoken of in a region from Turkey to a suite of closely related languages in Central Asia. Other languages like Mongolian and its kin as well as various Manchurian languages, Korean, and Japanese have been combined into an Altaic superfamily of languages that also show some deeper connections. There are even connections between the Na-Dene languages of some Native Americans and the Yedesian languages of what is now Russia, many thousands of miles away. And in addition to this there are connections between Basque and some of the languages of the Caucasus region, and between ancient Elamite as well as the Dravidian languages of southern India.
Given the general interest in understanding languages and making sense of them with the goal of decipherment and understanding the material and social culture of long ago societies, it has been unsurprising that people have sought to connect many of these ancient peoples together and have found that there were connections between very large groups that spread out over the entire world, such that the peoples who went into North America originally spoke a shared language to those who settled Europe as well as North Africa and Central and South Asia. But such a step cannot be taken all at once. We must first investigate the various branches and see how they connect to a common trunk, and see how it is that what was once a common tongue became many hundreds of widely separated tongues, many of them influenced by long-ago forgotten and extinct languages and increasing distances that led to divergent developments of a common tongue into languages whose connection only survives in tantalizing hints that are all too easy to dismiss if one does not know the larger historical and cultural connections at play.