Where do our words come from?

The same words, everywhere

Look at these four words in ten languages. They are spoken thousands of kilometres apart, yet they look like cousins.

That is not chance, and not just borrowing. These languages are one family. They all grew out of one older language, the way French, Spanish and Italian all grew out of Latin.

Nobody ever wrote it down

PIE was spoken roughly 6,000 years ago, around 4000 BC, long before writing. No book, no stone, no letter survives.

So how do we know any of it? Linguists compare the children, like detectives comparing family photos, and work backwards to the parent. A word with a star, like *tréyes, is a rebuilt word: no one has ever seen it written, but the evidence points to it.

The strange letters, like h₁ and h₂, are sounds that have disappeared from every living language. We know they were there because of the marks they left behind.

Herders on the grassland

Most scholars think PIE was spoken on the steppe: the huge open grassland north of the Black Sea and the Caspian Sea, in today’s Ukraine and southern Russia.

The people there herded cattle and sheep, drank milk, lived on the move and buried important people under big earth mounds called kurgans. Around 3300–2600 BC one group, the Yamnaya, spread across the whole steppe, from Hungary to Kazakhstan.

Ancient DNA (studies in 2015 and 2025) shows that people with Yamnaya ancestry then moved far into Europe and Asia, carrying their language with them. A 2025 study traced their ancestors further back, to people living between the Caucasus mountains and the lower Volga river around 4400–4000 BC.

Words on wheels

The steppe people had something new: wagons with wheels, pulled by oxen under a wooden yoke. With wagons, a whole family could live on the move with its herds.

The PIE words for these things still roll on today:

• *kʷékʷlos “wheel” → English wheel, Greek kýklos (so cycle, bicycle), Sanskrit chakra चक्र
• *yugóm “yoke” → English yoke, Latin iugum, Sanskrit yuga; yoga योग is “yoking” the mind
• *h₂éḱs- “axle” → English axle, Latin axis

Because everyone in the family shares these words, the parent language must have known wheels. Wheels appear only after about 3500 BC. That is one big clue to when PIE was spoken.

The horse question

PIE had a word for horse, *h₁éḱwos: Latin equus (so equestrian), Greek híppos (so hippodrome), Sanskrit aśva अश्व.

For a long time, people imagined the Yamnaya galloping across Europe on horseback. The truth is more careful:

• steppe people kept horses, ate them and perhaps drank mare’s milk;
• a 2024 DNA study of 475 ancient horses found that the modern domestic horse spread across Eurasia only around 2200 BC, after the big Yamnaya moves;
• other scientists (a 2026 study) argue that some Yamnaya already rode horses.

No word for the sea

Here is a clue in the other direction: there is no shared word for the sea. Each branch found its own:

PIE did have *néh₂us, “boat” (Latin navis → navy, Greek naus → nautical, Sanskrit नौ, Hindi नाव), and *móri, a lake or marsh (Latin mare, German Meer, Russian more), but only the European branches made that into “sea”. Greek thálassa was borrowed from people already living in Greece, and Sanskrit samudra means “where the waters gather”.

What their words tell us

Shared words also hint at what mattered to them:

• *gʰóstis “stranger, guest” → English guest, and Latin hostis “stranger, enemy” (→ hostile); hospes “host” (→ hospitality, hotel). A stranger was either a guest bound to you by duty, or an enemy.
• *péḱu “livestock” → Latin pecūnia “money”, Sanskrit paśu, and English fee: wealth was counted in cattle.
• *h₂r̥tós “fitting order” → Sanskrit ṛta, the right order of the world (the same root as order).
• Greek kléos áphthiton = Sanskrit śrávas ákṣitam: “imperishable fame”, a phrase so old both poets inherited it.

How one language became hundreds

As groups moved away and lost touch, their speech slowly changed, until each became a new language. Here is the simple picture:

• by about 2800 BC: into central and northern Europe (ancestors of Germanic, Celtic, Italic, Balto-Slavic)
• by about 2000 BC: Greek in Greece; Hittite in Anatolia (today’s Turkey), the first one written down, around 1650 BC
• by about 1500 BC: Indo-Iranian speakers in Iran and northern India; the oldest Sanskrit hymns, the Rig Veda

DNA tracks people, not words

Usually languages travel with people, but not always:

• North India: most South Asians carry some steppe ancestry, from under 10% to a little over 20%. It is absent from the Harappan genome at Rakhigarhi, so it arrived after the Indus civilisation declined, probably with the ancestors of Sanskrit. (Some in India dispute this and stress continuity with the Harappans.)
• Basques: they also carry steppe DNA. By about 2000 BC, newcomers with steppe ancestry had replaced about 40% of Iberia’s ancestry and nearly all its male lines, yet the Basques kept their own, non-Indo-European language: genes without language.
• Hungarians: the reverse. They speak a Uralic language but carry very little Uralic DNA: language without genes.

The branches of the tree

Not every language in Europe or India is in the family: Basque, Finnish and Hungarian in Europe, and Tamil, Telugu and other Dravidian languages in India, come from different families.

The detective trick: sound laws

Sounds change in regular ways. One famous example: where Latin, Greek and Sanskrit keep a p, English and German have an f.

Rules like this (this one is called Grimm’s law, found by Jacob Grimm of the fairy tales) let linguists rebuild PIE words step by step.

Other ideas

A different idea, the Anatolian hypothesis, says PIE spread much earlier, around 7000 BC, with the first farmers from Anatolia. Today most linguists and geneticists prefer the steppe story, because of the wheel words and the ancient DNA, but science keeps checking.

Every word has a journey

Each Word Story begins at Step 0 with its PIE root, then follows the word through Latin, Greek, French or Old English to the word you use today.