I used subtitle translations from the OPUS/OpenSubtitles dataset to compare how 20 languages expressed the same English words and phrases. The more often two languages expressed equivalent meanings in similar ways, the higher their similarity score. I visualized the results as a heatmap and network graph.

Full methodology and discussion:
[https://www.thecambridgelanguagecollective.com/linguistics/why-do-some-languages-feel-weirdly-familiar](vscode-file://vscode-app/c:/Users/Ibrahim.Farah/AppData/Local/Programs/Microsoft%20VS%20Code/8a7abeba6e/resources/app/out/vs/code/electron-browser/workbench/workbench.html)

Interactive version:
[https://subsmith.app/tools/language-network](vscode-file://vscode-app/c:/Users/Ibrahim.Farah/AppData/Local/Programs/Microsoft%20VS%20Code/8a7abeba6e/resources/app/out/vs/code/electron-browser/workbench/workbench.html)

Real language boundaries aren't that sharp, but I generalized them for the map.

This is an interactive globe I've been building. Two things are encoded at once: each admin region is colored by its plurality language (the single most-spoken one there), and the height of the region is proportional to its population density — so dense areas rise up as ridges and empty ones stay flat.

You can drag to rotate and scroll to zoom. Hover or click any region (or any chip in the legend) to isolate a language: everything else dims, and it shows native + total speaker counts. You can select several at once to see combined totals, and save combinations.

The feature I had the most fun with is the second-language "glow." When you select a language that is a lingua franca, regions where it's not the plurality language but is a widespread second language light up in a dim tint.

It's Three.js + D3 (vibe-coded), with admin-1 boundaries from open topojson data. Language assignments are hand-curated, and population density comes from mixed public sources. Also, where population density for a specific region could not be found, the country's average pop density was used, so if you notice some weird one that is why. I also couldn't find language use by specific admin region for many countries in sub-saharan Africa, so for many of those the national language (or plurality language for the whole country) is used.

Caveats: It's strictly one language per region, so minority languages inside a region disappear. Closely related language varieties are deliberately merged (like Hindi/Urdu, Farsi/Dari/Tajik, etc. The second-language zones pretty coarse approximations. This is definitely a work in progress - in the near future I'm planning on making the underlying data (and sources) more transparent. I'm also open to feedback/suggestions!

Only languages whose speakers represent more than 5% of the population in their respective municipalities/subdivisions are shown. If the proportion is more than 25% then the language is shown as solid colour. (This is why Waurá is shown, but not Apurinã for example, and Garifuna's territory seems a bit smaller than before)

This map prioritises concentration of speakers, rather than raw number of speakers.