Compare these three words. “Father”: Sanskrit pitṛ, Latin pater, Greek patēr. “Three”: Sanskrit trayas, Latin tres, Greek treis. Notice a pattern?
In 1786, in Calcutta, an English judge named William Jones noticed resemblances just like these — not just one or two, but reaching all the way down into the grammar itself. And he drew a conclusion: this kind of deep resemblance could not be an accident.
Resemblance has more than one explanation
Words can end up looking alike for several different reasons.
- Pure coincidence — with so many languages in the world, some words will just happen to sound similar.
- Borrowing — trade with a neighbor means borrowing useful words, the way English “tycoon” comes from Japanese.
- A shared parent — what was once a single language split apart over time into separate ones.
Jones was pointing at the third possibility. Why? Because the resemblance he’d spotted wasn’t the kind that borrowing could explain.
What can be borrowed, and what can’t
Words — especially names for new tools or foods — cross borders easily. But how a verb conjugates, or the basic scaffolding of a grammar, doesn’t transfer between languages nearly so easily. This still matches our own intuition today: English borrowed the word “tycoon” from Japanese, but that didn’t make English verbs start conjugating the Japanese way.
What Jones pointed to was exactly this hard-to-borrow layer — verb roots and grammatical form — matching up, astonishingly closely, between Sanskrit and Greek and Latin. So he drew his conclusion: these three languages must once have been a single language. They branched apart, at some point in the deep past, from a language that no longer exists.
Language as a family tree
This was a genuinely new way of looking at language — as a family tree. Just as people have grandparents and great-grandparents, languages might have ancestors too. Sanskrit, Greek, and Latin, on this view, are like cousins who never met each other’s common grandparent.
Jones went further, suggesting that Gothic (a distant ancestor of today’s German and Dutch) and Celtic (an ancestor of today’s Irish) belonged to the same family. That unspoken common ancestor is what later scholars would come to call “Proto-Indo-European.”
Why this was such a big deal
Jones wasn’t the first person to notice words like these looking alike. What made the difference was that a recognized authority said so, plainly, in public, for the first time. That single statement is what set off an entirely new field of study — comparative linguistics — dedicated to working out, with real method, how languages actually branch apart.
To see what else was in this discourse, taken one topic at a time, read Jones’s Discovery, Topic by Topic.