English mother, Latin māter, Greek mitéra, Russian matʹ, Hindi mātā, Persian mādar. One word, spoken five thousand years ago, mostly inherited and changed by every mouth that held it; Hindi mātā is a learned borrowing from Sanskrit.

Each column is one lineage, running from Proto-Indo-European at the top to its modern form at the bottom, grouped and coloured by branch. Pick a word in the control bar and watch what each branch did to it. That is the whole argument of comparative linguistics in one picture: the correspondences are too regular to be chance.

• Twelve languages to start with. The family has twenty-nine lineages here and the full sheet is a wall, so the chart opens on a dozen a general reader will know. The control bar widens it: twenty-two for the wider family, every lineage that attests the word on screen, or all twenty-nine including the dead ends — Hittite, Tocharian, Messapic, Thracian.
• A column that stops has no living descendant in its own line: Latin as a vernacular, Gothic, and the branches known only from inscriptions.
• Hover any cell for the stage, its dating, the sound change at work, and a citable source.
• Click a column to isolate one lineage; click again to release.
• An asterisk means reconstructed, not attested. Proto-Indo-European and the branch proto-languages are inferred from their descendants; nobody ever wrote them down.
• Forms appear in their own script where the stage had one, with romanisation beneath. The last row is banded because it is the payoff: that is where the words are still recognisably each other.
• On a phone the sheet scrolls sideways rather than shrinking to nothing. Downloading gives you the whole thing at print resolution.

Datings are conventional approximations and the deeper ones are contested. Sources per cell in the tooltips. Download renders the poster at print resolution entirely in your browser.

Elsewhere: The Same Idea · The Missing N · Flat-Foot · Polite Company · Signs for Sounds · The Second Alphabet · Twenty-Two Letters · Brahmi's Daughters · Heartwood · Every Language Family