| Germanic | English, German, Dutch, Swedish, Norwegian, Danish, Icelandic |
| Italic (Romance) | Italian, Spanish, French, Portuguese, Romanian |
| Celtic | Irish, Scottish Gaelic, Welsh, Breton |
| Hellenic | Greek |
| Anatolian | Hittite (extinct) |
| Tocharian | Tocharian A and Tocharian B (both extinct) |
| Indo-Iranian | Hindi, Urdu, Persian, Bengali, Punjabi, Marathi, Gujarati, Pashto, Kurdish |
| Balto-Slavic | Russian, Polish, Czech, Slovak, Bulgarian, Serbian, Croatian, Lithuanian, Latvian |
| Celtic | Irish, Welsh, Scottish Gaelic, Manx, Cornish, Breton |
| Armenian | Armenian |
| Hellenic | Greek |
| Albanian | Albanian |
